KAIST identifies a molecular “switch” that activates cell growth signaling, suggesting a potential basis for next-generation anticancer therapy
Cells carry their own growth switches. When enough nutrients—amino acids in particular—are available, cells flip this switch on and begin to grow. Researchers at KAIST and Yonsei University have now uncovered the molecular mechanism by which amino acid signals activate this cellular growth switch. The findings are expected to open a new avenue for anticancer therapies that target abnormal growth signaling in tumor cells.
KAIST (President Choongsik Bae) announced on July 26 that a research team led by Professors Hee-Sung Park and Jin Young Kang from the Department of Chemistry, working with Professor Sunghoon Kim's team from Yonsei University, has identified a molecular mechanism that links amino acid stimulation to mTORC1-dependent growth signaling.
Cells continually monitor whether enough amino acids—the basic building blocks of proteins—are available in their surroundings, and adjust their growth, protein synthesis, and energy use accordingly. Central to this process is mTORC1 (mammalian Target of Rapamycin Complex 1), a protein complex that functions as the cell's growth switch.
mTORC1 promotes cell growth, protein synthesis, and metabolism when nutrients and energy are abundant. But when mTORC1 becomes excessively active, cells can grow and proliferate beyond what is needed—a pattern of dysregulation observed in numerous cancers. For this reason, mTORC1 has long been considered a prime target for anticancer drug development. Exactly how cells detect external nutrient cues and translate them into mTORC1 activation, however, has remained incompletely understood.
The research team focused on the multi-tRNA synthetase complex (MSC), a large protein assembly composed of multiple aminoacyl-tRNA synthetases and scaffold proteins. While aminoacyl-tRNA synthetases are best known for their essential role in protein synthesis – attaching specific amino acids to their cognate tRNAs – the team showed that, in response to amino acid stimulation the MSC releases LARS1, thereby linking nutrient availability to growth signaling.
The key player within the MSC turned out to be a protein called LARS1 (leucyl-tRNA synthetase 1), an enzyme that attaches leucine to its corresponding tRNA and also functions as an intracellular leucine sensor. When cells receive a signal that nutrients are sufficient, LARS1 undergoes phosphorylation—a modification in which a small chemical tag is attached to a protein, altering its function or binding behavior.
The relationship can be pictured this way: the MSC is a control center where multiple proteins wait on standby, and LARS1 is the field agent dispatched to flip on the growth switch. When nutrients become abundant, LARS1 receives a phosphorylation "deployment signal," dissociates from IARS1, the protein that anchors LARS1 to the MSC, and is thereby released from the complex. The freed LARS1 then goes on to activate mTORC1.
In other words, when nutrients are scarce, LARS1 stays bound within the MSC and the growth signal remains off. Once nutrients become sufficient, LARS1 is released from the MSC and switches on mTORC1.
To investigate the structural basis of this process, the team used cryo-electron microscopy (cryo-EM), a technique that visualizes protein complexes in three dimensions in near-atomic resolution by rapidly freezing samples at extremely low temperatures. This allowed the researchers to determine how LARS1 and IARS1 bind to each other and to structurally explain how phosphorylation could disrupt their interaction.
The results showed that LARS1 and IARS1 are normally bound tightly, but amino acid stimulation induces the phosphorylation of LARS1, weakening its interaction with IARS1. This allows LARS1 to dissociate from the MSC and activate mTORC1.
The researchers also engineered phosphomimetic LARS1 variants—mutant proteins designed to imitate the phosphorylated state—and found that these variants substantially enhanced mTORC1 activity. This confirmed that the phosphorylation of LARS1 functions as the key molecular switch converting a nutrient signal into a cell growth signal.
The significance of this study lies in mapping, in concrete molecular detail, how cells sense amino acids and use that information to activate their growth switch. In particular, the study revealed that, upon receiving nutrient signals, the MSC—a complex involved in protein synthesis—releases its constituent protein LARS1, which then activates cellular growth signaling.
Some existing anticancer drugs work by directly inhibiting mTORC1, the cell's growth switch. However, because mTORC1 is also required for normal cellular growth and metabolism, its direct inhibition may also affect normal cells.
The research team expects that further identifying the kinase responsible for phosphorylating LARS1, along with its regulatory mechanism, could enable a more precise anticancer strategy—one that intercepts the growth signal further upstream, before it reaches mTORC1, rather than blocking mTORC1 itself.
The study was co-first-authored by Youjin Kim and Joo-Chan Kim from KAIST's Department of Chemistry and was published online in Nature Communications on June 11.
Paper title: Cryo-EM structure of the LARS1:IARS1 complex reveals a nutrient-responsive switch controlling mTORC1 signaling
DOI: https://doi.org/10.1038/s41467-026-74085-x
This work was supported by the National Research Foundation of Korea (grant nos. RS-2026-25482352 to H.S.P., RS-2024-00344154 to J.Y.K., and NRF-2021R1A3B1076605 to S.K.) and PNCC (grant no. 160183).
KAIST Gives Antibodies “Eyes” to Detect Cancer, Targeting Cancer Mutations Inside Cells
Antibodies are like “guided missiles” that find and attack cancer cells, but cancer-causing mutations inside cells have remained a “blind spot” for treatment because antibodies cannot reach them. KAIST researchers have now succeeded in precisely targeting even intracellular cancer mutations using a newly designed antibody created through computational methods. This achievement is expected to open a new path toward next-generation precision therapies for difficult-to-treat cancers, going beyond the limitations of conventional antibody treatments.
KAIST (President Choongsik Bae) announced on the 24th of July that a research team led by Professor Byung-Ha Oh from the Department of Biological Sciences, together with researchers from Therazyne, a KAIST faculty startup specializing in protein design and headed by Professor Oh, has developed an antibody that selectively recognizes only cancer cells carrying KRAS(G12D), a representative cancer-driving mutation. By combining computational antibody design with experimental validation, the team designed a new antibody that would have been difficult to develop through conventional approaches and is now verifying its efficacy in animal disease models.
KRAS(G12D) is a mutated form of the KRAS protein, which regulates cell growth and proliferation. It is one of the most common cancer-driving mutations found in pancreatic, colorectal, and lung cancers. However, because the KRAS protein exists inside cells, it has long been considered an “undruggable target” that is difficult to directly target with conventional antibody therapeutics.
The research team focused on the natural process by which cells break down aged or damaged proteins into small fragments. The KRAS(G12D) protein inside cells is also processed in this way into small protein fragments, known as neoantigens, which serve as clues that allow immune cells to distinguish cancer cells. Some of these fragments are then transported to the cell surface and presented to immune cells. By combining computational protein design with experimental screening, the team developed a TCR-like antibody that precisely recognizes only this cancer-mutation-derived fragment.
TCR, or T cell receptor, acts as a “sensor” that allows T cells, the body’s immune cells, to read protein fragments displayed on the surface of cells and identify cancer cells or virus-infected cells. The TCR-like antibody developed in this study works on a similar principle, effectively giving an antibody the “eyes” of a T cell. It was designed to selectively recognize traces of intracellular cancer mutations that conventional antibodies cannot easily access.
Experimental results confirmed that the antibody developed by the team selectively recognizes only cancer cells carrying the KRAS(G12D) mutation, while showing little to no reaction with normal cells or other proteins. When applied to immunotherapy, it was also shown to effectively eliminate only cancer cells carrying the mutation. This finding suggests the possibility of expanding antibody therapy to intracellular cancer-driving proteins that conventional antibody treatments have been unable to target. It is also expected to serve as a platform technology for developing next-generation precision antibody therapies targeting not only KRAS but also a wide range of cancer mutations.
Professor Byung-Ha Oh said, “The antibody developed in this study can selectively identify only cancer cells carrying the KRAS(G12D) mutation, demonstrating the potential for precision antibody therapeutics that minimize damage to normal cells.” He added, “The computational antibody design technology developed in this research is expected to be widely applicable to the development of next-generation antibody therapeutics targeting KRAS as well as various other cancer mutations.”
Both the first author and corresponding authors of this study are KAIST-affiliated researchers. SangPhil Ahn, a researcher at Therazyne, participated as the first author, while Professor Byung-Ha Oh and Bo-Seong Jeong, Head of Research at Therazyne, jointly led the study as co-corresponding authors. The research was published online on June 3 in Molecular Therapy, a leading international journal in the field of gene and cell therapy.
Paper title: Discovery of TCR-like antibodies to the KRAS G12D neoantigen via in silico-in vitro workflow DOI: https://doi.org/10.1016/j.ymthe.2026.05.032
This research was conducted in collaboration with Therazyne and the New Drug Development Center of the Osong Biomedical Innovation Foundation, and was supported by the Ministry of Science and ICT’s Industry-Academia-Research Linked New Drug Development Program and the National Research Foundation of Korea’s Bio & Medical Technology Development Program.
KAIST Develops a Molecular Platform for the Selective Control of Oxygen Reaction Pathways
Controlling how oxygen reacts is important for improving technologies such as batteries, fuel cells, and environmentally sustainable chemical processes. A KAIST research team has developed a new molecular system that can selectively switch the pathway through which electrons are transferred during oxygen activation. The findings are expected to provide a fundamental design principle for next-generation catalysts and energy-conversion technologies.
KAIST (President Choongsik Bae) announced on the 22nd of July that a research team led by Professor Seung Jun Hwang from the Department of Chemistry has developed a molecular system capable of directing oxygen activation along a selected electron-transfer pathway. By combining germanium with a molecular framework that can store and transfer electrons, the team established a design principle for selectively switching oxygen activation between two- and four-electron pathways.
Catalysts for controlling oxygen reactions have traditionally been developed around transition-metal centers such as iron, cobalt, and nickel. Germanium, by contrast, is a main-group element in the same group of the periodic table as silicon and has generally been considered less suitable for reactions requiring the coordinated transfer of several electrons.
To overcome this limitation, the research team combined germanium with a redox-active ligand, a molecular framework capable of storing, accepting, and transferring electrons. The ligand serves as an electron reservoir and cooperates with the germanium center, allowing the entire molecular structure to participate in multielectron reactions.
When oxygen reacts, the products and reaction outcomes depend on whether two or four electrons are transferred. In general, two-electron oxygen reduction produces hydrogen peroxide, while four-electron reduction produces water. Selectively controlling these pathways is therefore an important challenge in the development of batteries, fuel cells, and greener chemical catalysts.
The study presents a rare example of a main-group molecular system in which two- and four-electron reactivity can be selectively accessed within the same underlying molecular framework. This approach broadens the range of elements that may be considered in catalyst design and provides an alternative strategy to relying exclusively on transition metals.
The team also succeeded in isolating and analyzing a germanium compound representing the two-electron stage of the reaction, which they stabilized by attaching a methyl group to the germanium complex. Remarkably, the germanium atom in this compound could both donate and accept electrons, providing an important clue to how the system controls different reaction pathways.
The team also confirmed the practical potential of the new system. Under mild, light-free conditions, the germanium complex removed halogen atoms such as bromine and chlorine from organic compounds and regenerated alkenes (organic compounds containing a carbon-carbon double bond), which are widely used as raw materials for pharmaceuticals, plastics, and other chemical products. These results suggest that useful chemical feedstocks could be produced through simpler and potentially more energy-efficient processes.
“We expect these findings to inform the development of next-generation catalysts for energy conversion and to contribute to more selective and efficient chemical processes.” said Professor Hwang.
The study was conducted by Sung Gyu Kim and Jinrok Oh, currently postdoctoral researchers in the KAIST Department of Chemistry, and Dae Eui Choi, a student in the combined master’s and doctoral program in the Department of Chemistry at POSTECH. The results were published online in the international journal Chem on July 6.
Paper title: Germanium Ligand Redox Cooperativity: A Key to Ambiphilicity and Switchable Two- and Four-Electron Transfer
DOI: 10.1016/j.chempr.2026.103127
This work was supported by National Research Foundation of Korea grants funded by the Korean government through the Ministry of Science and ICT (NRF-2021R1C1C1010220 and RS-2025-02216980), and by the Samsung Science and Technology Foundation under Project No. SSTF-BA2101-09. Sung Gyu Kim received research fellowship support from the Basic Science Research Program through the National Research Foundation of Korea, funded by the Ministry of Education (RS-2024-00415390).
KAIST’s Advanced Oocyte and Embryo Analysis Technology to Improve IVF Success Recognized at Leading Global Conference
Accurately selecting oocytes and embryos with high developmental potential is essential for improving the success rate of in vitro fertilization (IVF). KAIST researchers have developed a foundational technology that combines time-lapse imaging, which continuously tracks changes over time, with quantitative three-dimensional analysis to predict developmental potential at an early stage without damaging live oocytes and embryos.
KAIST (President Choongsik Bae) announced on July 21 that Dr. Chungha Lee, a postdoctoral researcher in Professor YongKeun Park’s research group in the Department of Physics, received the Basic Science Award for poster presentation at the 2026 Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE), the world’s largest reproductive medicine conference, held in London, United Kingdom, in July.
The Basic Science Award for poster presentation recognizes the most outstanding poster in the basic science category at the ESHRE Annual Meeting, which attracts more than 10,000 participants each year. After reviewing submitted abstracts, the society selects five candidate studies and determines the final winner based on a comprehensive evaluation of the on-site poster presentation and question-and-answer session.
The award recognizes the originality and academic significance of applying holotomography—a technology that uses information about the refraction of light to image the internal structures of live cells in three dimensions without damaging them—to the field of reproductive medicine.
The research demonstrates the potential to develop a next-generation assessment technology that can non-invasively monitor changes in live oocytes and embryos over time, quantitatively analyze them in three dimensions, and predict their developmental potential at an early stage. It also presents a pathway for advancing conventional two-dimensional oocyte and embryo assessment, which has relied heavily on expert experience, toward a more objective and quantitative three-dimensional approach.
In IVF procedures, the selection of oocytes and embryos is a critical factor determining the likelihood of pregnancy. However, because oocytes and embryos are cells that may ultimately be transferred to patients, analytical methods involving stains or fluorescent markers that could affect the cells are difficult to apply.
Clinical practice currently relies primarily on Hoffman modulation contrast microscopy and phase-contrast microscopy, which visualize cellular morphology using differences in light intensity and phase without staining the cells. Embryologists—specialized medical professionals who culture and assess oocytes and embryos during IVF procedures—select embryos for transfer by examining characteristics such as their shape, size, cell-division status, and developmental timing using these microscopes.
However, current assessment methods have limitations because they depend mainly on two-dimensional images and the experience of embryologists, making them largely qualitative. There has therefore been a continuing demand for more objective and quantitative assessment methods.
To overcome these limitations, the research team applied holotomography. This label-free technique requires neither cellular staining nor fluorescent markers. Instead, it measures how light is refracted as it passes through a cell, enabling the internal structure of a live cell to be imaged in three dimensions without causing damage.
The technology can also quantitatively measure the refractive index, which varies according to the density and composition of intracellular materials, allowing researchers to analyze even subtle changes in cellular structure.
Using holotomography, the researchers analyzed the internal structures of oocytes and embryos in three dimensions while keeping them alive and intact. Through experiments using mouse models, they also demonstrated that various biophysical features obtained from early-stage embryos could be used to predict their subsequent development.
Furthermore, the study demonstrated that combining quantitative measurements with artificial intelligence (AI) analysis could enable more advanced assessment of oocytes and embryos beyond conventional morphological assessment, which primarily evaluates features such as cell shape and size.
The related studies have been submitted to international academic journals and are currently under review.
※ Papers: Title: Label-free 3D subcellular phenotyping of mouse embryos by holotomography enables early prediction of blastocyst formation
Journal: bioRxivDOI: https://doi.org/10.1101/2024.05.07.592317
Title: Holotomography reveals biophysical remodeling of mouse oocytes during post-ovulatory aging
Journal: bioRxiv
DOI: https://doi.org/10.64898/2026.06.18.733271
The research was conducted through an industry–academia–clinical collaboration involving the KAIST Department of Physics, the Fertility Center at CHA Bundang Medical Center led by Professor Ji Hyang Kim, Avenues, and Tomocube.
It represents a notable example of interdisciplinary research in which an advanced optical platform developed through fundamental physics research was applied to the field of reproductive medicine.
“This award is particularly meaningful because it demonstrates that a new approach for quantitatively analyzing live oocytes and embryos in three dimensions without damaging them has been recognized for its academic value in reproductive medicine,” said Professor Park.
“We are currently conducting validation studies using human oocytes. We will continue our research to develop this approach into an objective and accurate technology for assessing oocytes and embryos and ultimately contribute to improving the success rate of fertility treatment.”
The research was supported by the Global Leader Research Program of the National Research Foundation of Korea and the Research-Centered Hospital R&D Program of the Korea Health Industry Development Institute.
KAIST Enables DNA Synthesis Using Only Temperature Instead of Chemical Reagents
"Complex chemical processes are essential for making DNA." This long-held assumption in the field of biotechnology has been overturned by a Korean research team. A KAIST research team has developed the world's first foundational technology that enables the synthesis of desired DNA using only temperature. Using this technology, the team also demonstrated a "DNA temperature black box" that records temperature changes during shipping without electricity.
KAIST announced on the 7th of July that a research team led by Professor Yeongjae Choi of the Graduate School of Engineering Biology, in collaboration with ATG Lifetech Inc. (CEO Taehoon Ryu) and a research team led by Professor Hansol Choi from the Department of Life Science at Ewha Womans University, has developed this platform technology that synthesizes desired DNA sequences by controlling only temperature.
DNA is the "blueprint" that contains the genetic information of humans and all other living organisms. Scientists use custom-made DNA in various biotechnology applications, such as diagnosing diseases, developing new drugs, and creating microorganisms with new functions. Until now, however, each time one of the four bases that make up DNA—A, T, G, and C—was connected, chemical reagents had to be added and washed out repeatedly. As a result, costly automated DNA synthesis equipment and specialized research facilities were essential.
To overcome these limitations, the research team developed "hairpin DNA that reacts only at specific temperatures." This hairpin DNA is a special DNA structure that remains folded like a hairpin and unfolds only at a certain temperature. The team placed multiple types of hairpin DNA that operate at different temperatures into a single test tube and succeeded in synthesizing desired DNA step by step by changing only the temperature in the sequence.
This opens the way for synthesizing DNA with only a general temperature control device, without the need for complex reagent replacement or large-scale equipment.
As the technology advances, it is expected to greatly reduce the cost and time required to make DNA, lowering the entry barriers not only for synthetic biology and genetic research, but also for various bioindustries such as drug development and precision medicine.
To demonstrate the practical applicability of the technology, the research team also implemented a power-free "DNA temperature black box." This device is normally stored in a freeze-dried state and begins operating when a single drop of water is added just before use. It then automatically records—directly into a DNA sequence—when, how long, and in what order the temperature changes during shipping. In addition, when exposed to temperatures above a certain level, the device changes color, allowing abnormalities to be checked visually on the spot. It is expected to be used for the quality control of products for which cold-chain distribution is important, such as vaccines, biopharmaceuticals, cell therapies, and fresh foods.
KAIST researcher Jangho Choi and GIST doctoral student Jinho Kim participated in this research as co-first authors, and the research results were published in the international journal Nature Communications on July 2.
※ Paper title: Programmable one-pot polymerase-mediated DNA synthesis via temperature control
※ DOI: https://doi.org/10.1038/s41467-026-74890-4
※ Related Video: https://drive.google.com/file/d/1bUtzC83qIm1k-hNFKTb09yFPhfsD4iU-/view?usp=drive_lin
※ Authors: Jangho Choi (KAIST, co-first author), Jinho Kim (GIST, co-first author), Hansol Choi (Ewha Womans University, corresponding author), Yeongjae Choi (KAIST, corresponding author)
This research was supported by the Ministry of Science and ICT through the Future Promising Convergence Technology Pioneer Program, the Biofoundry-Based Technology Development Program, the Young Researcher Program, and the Global Basic Research Laboratory Program.
KAIST: Dementia-Causing Substance Turns On a Therapeutic “Switch”
A substance that worsens dementia has become a “switch” that initiates treatment. KAIST researchers have developed a new therapeutic approach that uses hydrogen peroxide (H₂O₂), a reactive oxygen species that damages cells and increases in the brains of patients with Alzheimer’s disease, to activate a drug selectively in diseased brain tissue. The team also confirmed improvements in cognitive function through animal experiments, presenting a new possibility for next-generation dementia treatment.
KAIST announced on the 2nd that a research team led by Professor Mi Hee Lim of the Department of Chemistry, in collaboration with Professor Mingeun Kim of Chonnam National University, Dr. Chul-Ho Lee and Dr. Kyoung-Shim Kim of the Korea Research Institute of Bioscience and Biotechnology, and Dr. Young-Ho Lee of the Korea Basic Science Institute, has developed a prodrug that is activated selectively in the diseased brain in Alzheimer’s disease and confirmed its therapeutic effects through animal experiments.
A prodrug is a drug that initially has minimal therapeutic effect but is converted into an active therapeutic agent only under specific conditions inside the body. In this study, the prodrug was designed to be activated only when it encounters hydrogen peroxide, which increases in the brains of patients with Alzheimer’s disease, allowing it to function as a “smart therapeutic agent” that selectively acts in diseased brain tissue.
In the brains of Alzheimer’s disease patients, hydrogen peroxide, which damages cells, is elevated above normal levels. Until now, it has generally been regarded only as a harmful substance that should be removed. However, the research team devised a method to use it instead as a signal that activates a drug.
The prodrugs developed by the research team, BE-1 and BE-2, are designed to remain minimally reactive in a healthy brain. However, when they encounter hydrogen peroxide in a brain affected by dementia, they are converted into active therapeutic compounds, AP-1 and AP-2. Through this process, they reduce reactive oxygen species, including hydrogen peroxide, while also preventing amyloid beta (Aβ) peptides — peptides known as a major cause of dementia that accumulate in the brain and damage nerve cells — from aggregating into highly toxic clumps.
Using advanced analytical techniques, the research team confirmed that the activated drug alters the morphology of amyloid beta aggregates and suppresses their growth into large aggregates.
These effects were also confirmed in Alzheimer’s disease mouse models. The drug crossed the blood-brain barrier (BBB), a protective barrier that controls whether substances in the blood can enter the brain, and was converted into the therapeutic compound inside the diseased brain. In mice that received long-term drug administration, oxidative stress in the hippocampus, which is responsible for memory, was reduced, and amyloid beta accumulation in the brain also decreased. In behavioral experiments assessing the ability to recognize new objects and navigate mazes, cognitive function was also found to improve.
This study is significant in that the drug was designed to operate only where needed by using the environment of the diseased brain itself. This approach presents a new strategy for dementia treatment that can enhance therapeutic efficacy while reducing side effects, and it is expected to be applicable to the treatment of other neurodegenerative diseases, such as Parkinson’s disease.
Professor Mi Hee Lim of KAIST’s Department of Chemistry said, “This study is meaningful in that hydrogen peroxide, which had previously been regarded only as something to be eliminated, was used as a signal to activate a drug. We expect this strategy, which activates drugs in diseased tissue, to become a new platform for treating complex diseases such as Alzheimer’s disease more safely and effectively.”
This study was co-first-authored by Jimin Lee and Eunseo Hong, Ph.D. candidates in KAIST’s Department of Chemistry, and was published online on May 31, 2026, in the international journal Small (Impact Factor: 12.1, top 10% in the field of chemistry).
※ Paper title: A Prodrug Approach for Activity-Based Chemical Modulation toward Multiple Pathological Targets in Alzheimer’s Disease
DOI: 10.1002/smll.74013
This research was supported by the National Research Foundation of Korea’s Leader Researcher Program, Global Leading Research Center Program, Sejong Science Fellowship, Graduate Student Research Encouragement Program, and institutional programs of KRIBB and KBSI.
How Does Superconductivity Begin? Unveiling the Hidden Flow of Electrons
Superconductivity, a phenomenon where electricity flows without resistance, is considered the core of quantum computers and next-generation power technologies. However, the exact states electrons undergo before superconductivity emerges have not yet been fully elucidated. KAIST researchers have provided experimental clues revealing the hidden order electrons form prior to superconductivity in a kagome metal, a material closely related to superconducting phenomena. The team confirmed that a loop-like circulating order of electrons (loop-current order) emerges earlier than the periodic clustering of electrons (charge density wave).
KAIST (President Kwang Hyung Lee) announced on the 30th that a joint research team led by Professors Yeongkwan Kim, Myung Joon Han, and SungBin Lee from the Department of Physics discovered through circular dichroism angle-resolved photoemission spectroscopy (CD-ARPES) experiments and theoretical calculations that time-reversal symmetry breaking occurs at a higher temperature than the charge density wave formation in the kagome metal CsV3Sb5. Time-reversal symmetry is a property where physical phenomena appear identical even when time is reversed. The breaking of this symmetry implies that electrons within the material may have created a hidden flow with a specific directionality.
A kagome metal is a material with a repeating triangular atomic arrangement, resembling the traditional Japanese basket weaving pattern 'kagome'. In this structure, electrons interact strongly with each other, giving rise to various quantum phenomena rarely seen in normal metals, such as charge density waves, superconductivity, and topological electronic states. In particular, CsV3Sb5 exhibits both charge density waves and superconductivity at low temperatures, drawing attention as a crucial platform for next-generation quantum materials research.
However, there has been an ongoing debate over whether another hidden electronic order exists between the charge density wave and superconductivity in this material. Although several experiments have reported signals suggesting broken time-reversal symmetry, it was unclear whether this phenomenon was a consequence of the charge density wave formation or an independent electronic order that emerges prior to it.
To resolve this debate, the research team alternately irradiated high-quality CsV3Sb5 single crystals with left- and right-circularly polarized light and precisely measured the difference in the intensity of the emitted electrons. They then eliminated spurious signals potentially caused by the experimental setup's geometry, isolating only the intrinsic signals originating from the symmetry breaking of the material itself.
As a result, they confirmed that the signal of time-reversal symmetry breaking already appears around 140~145 K, which is significantly higher than the charge density wave formation temperature of about 94 K. This supports the interpretation that electrons form a loop-current order—a microscopic loop-like circulation—before creating the charge density wave pattern. The loop-current order is an electronic order where electrons behave as if flowing along small loops within the atomic lattice; it was theoretically proposed long ago but has been difficult to verify experimentally.
The team also tracked how the electronic structure changed as the temperature was lowered. At high temperatures, a normal metallic state appeared; at lower intermediate temperatures, the loop-current order formed first. As the temperature decreased further, a complex state evolved where the charge density wave intertwined with the loop-current order, eventually leading to the superconducting state. This research proposes a hierarchical structure of phase transitions in CsV3Sb5, progressing from 'loop-current order → charge density wave → superconductivity'.
This achievement provides a crucial clue for understanding the fundamental principles of superconductivity. It is not yet fully understood what kind of order electrons form before superconductivity occurs, or which electronic orders compete or cooperate with superconductivity. By demonstrating the existence of an electronic state with broken time-reversal symmetry prior to the superconducting state, this study offers an important lead in understanding unconventional superconductivity, which operates differently from standard mechanisms.
Furthermore, this research is expected to help understand hidden electronic orders in other superconducting materials beyond kagome metals. In particular, it could serve as a reference for explaining the peculiar electronic state (pseudogap) prior to superconductivity, which has long been discussed in cuprate high-temperature superconductors.
Professor Yeongkwan Kim stated, "This research is the result of directly tracking the time-reversal symmetry breaking of a kagome metal within its electronic structure, which had previously only been discussed through indirect signals. By showing the sequence in which electrons form order before reaching superconductivity, we have presented a new reference point for research on unconventional superconductivity and strongly correlated quantum materials.“
Professor Myung Joon Han added, "The key point is that the circular dichroism signal observed in the experiment aligns perfectly with the electrons' orbital motion pattern (orbital angular momentum pattern) expected from the loop-current order. This is a case where we uncovered the microscopic origin of the hidden electronic order by combining experiment and theory.“
KAIST Department of Physics researchers Jaehun Cha, Hyunggeun Lee, and Sangjun Sim participated as co-first authors in this study. The research findings were published online in the international physics journal Nature Physics on June 15, 2026.
Paper Title: Evidence of time-reversal symmetry breaking above the charge density wave order in a kagome metal
DOI: https://doi.org/10.1038/s41567-026-03331-2
This research was supported by the Mid-Career Researcher Program and the Accelerator Manpower Training Program (Ministry of Science and ICT, National Research Foundation of Korea), the Korea Research Institute of Standards and Science (KRISS), the Air Force Office of Scientific Research (AFOSR), and the US Department of Energy's Basic Energy Sciences (DOE BES).
KAIST-KBSI, ‘Communication’ Between Proteins Found to Mitigate Alzheimer’s Toxicity… Opening the Path to Treatment
50 million people worldwide are estimated to have dementia, with Alzheimer’s disease—accounting for over 70%—being the representative neurodegenerative brain disorder. A Korean research team has, for the first time in the world, identified at the molecular level that tau and amyloid-β, the two key pathological proteins of Alzheimer’s disease, directly communicate to regulate toxicity. This achievement is expected to provide new insights into the pathophysiology of Alzheimer’s disease, as well as important clues for discovering biomarkers for early diagnosis and developing therapeutics for neurodegenerative brain disorders.
KAIST (President Kwang Hyung Lee) announced on the 24th of August that Professor Mi Hee Lim’s research team in the Department of Chemistry (Director of the Research Center for Metal–Neuroprotein Interactions), in collaboration with Dr. Young-Ho Lee’s team from the Division of Advanced Biomedical Research at the Korea Basic Science Institute (KBSI, President Sung-kwang Yang) under the National Research Council of Science & Technology (NST, Chairperson Yeung-Shik Kim), together with Dr. Yun Kyung Kim and Dr. Sung Su Lim from the Brain Science Institute at the Korea Institute of Science and Technology (KIST, President Sang-Rok Oh), has elucidated at the molecular level that the microtubule-binding domain of tau—one of the major pathological proteins of Alzheimer’s disease—directly interacts with amyloid-β (tau–amyloid-β communication), alters its aggregation pathway, and alleviates cellular toxicity.
Pathologically, Alzheimer’s disease is characterized by the accumulation of“neurofibrillary tangles” formed by aggregates of tau, a protein responsible for transporting nutrients and signaling molecules within neurons, and “amyloid plaques (senile plaques)” formed by clusters of amyloid-β fragments—abnormally cleaved from amyloid precursor protein, which is involved in brain development, intercellular signaling, and neuronal recovery—that aggregate in and around neuronal membranes in the brain.
Although tau and amyloid-β form pathological structures in spatially separated locations, it has been suggested that they may coexist inside and outside of cells and potentially interact. However, the molecular-level understanding of how their direct interaction affects the onset and progression of the disease has not been clearly revealed until now.
The joint research team found that among the structural repeats of tau protein that bind to microtubules (the intracellular transport system) inside neurons—K18, R1–R4, PHF6*, and PHF6—specifically K18, R2, and R3 bind with amyloid-β to form ‘tau–amyloid-β heterocomplexes.’ This process is significant because amyloid-β normally assembles into highly toxic, rigid fibers (amyloid fibrils), but when certain tau regions bind, amyloid-β shifts to an aggregation pathway that produces less toxic, less rigid aggregates.
Notably, these repeat regions of tau delay the nucleation stage (the initial step of amyloid aggregation linked to disease onset) and simultaneously alter the aggregation speed and structural form of amyloid-β associated with disease progression. As a result, the toxicity caused by amyloid-β was markedly reduced in both the intracellular and extracellular environments of the brain.
In this study, the team combined precise analytical techniques—including spectroscopy, mass spectrometry, isothermal titration calorimetry, and nuclear magnetic resonance—with cell-based toxicity assays to comprehensively analyze the structural, thermodynamic, and functional properties of tau–amyloid interactions.
The findings revealed that specific regions of tau’s microtubule-binding repeats possess both hydrophilic (water-attracting) and hydrophobic (water-repelling) characteristics, and when the balance of these two properties is optimized, tau binds more effectively to amyloid-β. In other words, the intrinsic properties of tau determine its binding affinity with amyloid-β, its modulation of aggregation pathways, and its ability to regulate toxicity.
Dr. Young-Ho Lee of KBSI stated, “This research has uncovered a new molecular mechanism for the onset and progression of dementia, an intractable neurodegenerative disease. In particular, multidisciplinary convergent research focused on molecular interactions and protein aggregation is expected to play a pivotal role in clarifying not only the cross-talk between Alzheimer’s and Parkinson’s diseases but also the interconnections among various diseases such as dementia, diabetes, and cancer.”
Professor Mi Hee Lim of KAIST added, “Tau protein does not merely contribute to pathological formation, but rather, through specific microtubule-binding repeat structures, it exerts a molecular function that actively mitigates amyloid-β aggregation and toxicity. This provides a new turning point in the pathological understanding of Alzheimer’s disease. The significance of this study lies in identifying new molecular motifs that could serve as therapeutic targets not only for Alzheimer’s but also for a variety of protein aggregation-based neurodegenerative brain disorders.”
This research, with Dr. Min Geun Kim of KAIST’s Department of Chemistry as first author, was published on August 22 in the internationally renowned journal Nature Chemical Biology (Impact factor: 13.7, top 3.8% in the field of chemistry).
※ Paper Title: “Interactions with tau’s microtubule-binding repeats modulate amyloid-β aggregation and toxicity”
※ DOI: 10.1038/s41589-025-01987-0
This research was supported by the National Research Foundation of Korea’s Basic Research Program (Leader Research and Mid-career Researcher Program), the Sejong Science Fellowship, as well as KBSI and KIST.
New and Highly Efficient Recycling Technology to Turn Used Tires into Raw Materials for Rubber and Nylon
< (From left) Kyungmin Choi (MS-Ph.D. integrated course, Department of Chemistry), Dr. Beomsoon Park, Professor Soon Hyeok Hong, Dr. Kyoungil Cho >
Approximately 1.5 billions of tires are discarded globally every year, and this is identified as one of the major causes of serious environmental pollution. The research team at the Department of Chemistry at KAIST has achieved a breakthrough by selectively converting waste tires into high-purity cyclic alkenes, valuable chemical building blocks used in the production of rubber and nylon fibers. This advance marks a new milestone in chemical recycling technology for waste tires.
The team, led by Professor Soon Hyeok Hong, has developed a dual-catalyst-based reaction system that overcomes the long-standing challenges associated with recycling vulcanized rubber materials.
Tires are composed of complex blends of synthetic and natural rubber, and their physical strength and durability are reinforced with additives such as silica, carbon black, and antioxidants. In particular, cross-linking between rubber chains is formed through the vulcanization process, giving them a structure resistant to heat and pressure, which is one of the main reasons why chemical recycling of waste tires is difficult.
Until now, waste tire recycling has mainly relied on pyrolysis or mechanical recycling methods. The pyrolysis method is a technology that decomposes polymer chains at high temperatures of 350-800°C to convert them into fuel oil, but it clearly has limitations such as high energy consumption, low selectivity, and the production of low-quality hydrocarbon mixtures.
To solve these problems, the research team developed a method to convert waste rubber into useful chemicals using dual catalysis. The first catalyst helps to break down rubber molecules by changing their bonding structure, and the second catalyst creates cyclic compounds through a ring-closing reaction.
This process shows high selectivity of up to 92% and a yield of 82%. The produced cyclopentene can be recycled into rubber, and cyclohexene can be used as a raw material for nylon fibers, making them industrially very valuable.
The research team successfully applied the developed system to discarded waste tires, achieving selective conversion into high-purity cyclic alkenes. Unlike the existing pyrolysis method, this is evaluated as a new turning point in the field of waste tire recycling as it can produce high-value chemicals through low-temperature precision catalytic reactions.
In addition, this catalytic platform is compatible with a wide range of synthetic and waste rubbers, positioning it as a promising foundation for scalable, circular solutions in the polymer and materials industries.
< Figure 1. Development of a Catalytic Method for Chemical Recycling of Waste Rubber >
Professor Hong stated, "This research offers an innovative solution for the chemical recycling of waste tires. We aim to develop next-generation high-efficiency catalysts and lay the groundwork for commercialization to enhance economic feasibility. Ultimately, our goal is to contribute to solving the broader waste plastic problem through fundamental chemistry."
This research, in which Beomsoon Park, Kyoungil Cho, and Kyungmin Choi participated, was supported by the National Research Foundation of Korea and was published online in the internationally renowned academic journal ‘Chem’ on June 18th.
※Paper Title: Catalytic and Selective Chemical Recycling of Post-Consumer Rubbers into Cycloalkenes
※DOI: 10.1016/j.chempr.2025.102625
Simultaneous Analysis of 21 Chemical Reactions... AI to Transform New Drug Development
< Photo 1. (From left) Professor Hyunwoo Kim and students Donghun Kim and Gyeongseon Choi in the Integrated M.S./Ph.D. program of the Department of Chemistry >
Thalidomide, a drug once used to alleviate morning sickness in pregnant women, exhibits distinct properties due to its optical isomers* in the body: one isomer has a sedative effect, while the other causes severe side effects like birth defects. As this example illustrates, precise organic synthesis techniques, which selectively synthesize only the desired optical isomer, are crucial in new drug development. Overcoming the traditional methods that struggled with simultaneously analyzing multiple reactants, our research team has developed the world's first technology to precisely analyze 21 types of reactants simultaneously. This breakthrough is expected to make a significant contribution to new drug development utilizing AI and robots.
*Optical Isomers: A pair of molecules with the same chemical formula that are mirror images of each other and cannot be superimposed due to their asymmetric structure. This is analogous to a left and right hand, which are similar in form but cannot be perfectly overlaid.
KAIST's Professor Hyunwoo Kim's research team in the Department of Chemistry announced on the 16th that they have developed an innovative optical isomer analysis technology suitable for the era of AI-driven autonomous synthesis*. This research is the world's first technology to precisely analyze asymmetric catalytic reactions involving multiple reactants simultaneously using high-resolution fluorine nuclear magnetic resonance spectroscopy (19F NMR). It is expected to make groundbreaking contributions to various fields, including new drug development and catalyst optimization.
*AI-driven Autonomous Synthesis: An advanced technology that automates and optimizes chemical substance synthesis processes using artificial intelligence (AI). It is gaining attention as a core element for realizing automated and intelligent research environments in future laboratories. AI predicts and adjusts experimental conditions, interprets results, and designs subsequent experiments independently, minimizing human intervention in repetitive experiments and significantly increasing research efficiency and innovativeness.
Currently, while autonomous synthesis systems can automate everything from reaction design to execution, reaction analysis still relies on individual processing using traditional equipment. This leads to slower speeds and bottlenecks, making it unsuitable for high-speed repetitive experiments.
Furthermore, multi-substrate simultaneous screening techniques proposed in the 1990s garnered attention as a strategy to maximize reaction analysis efficiency. However, limitations of existing chromatography-based analysis methods restricted the number of applicable substrates. In asymmetric synthesis reactions, which selectively synthesize only the desired optical isomer, simultaneously analyzing more than 10 types of substrates was nearly impossible.
< Figure 1. Conventional organic reaction evaluation methods follow a process of deriving optimal reaction conditions using a single substrate, then expanding the substrate scope one by one under those conditions, leaving potential reaction areas unexplored. To overcome this, high-throughput screening is introduced to broadly explore catalyst reactivity for various substrates. When combined with multi-substrate screening, this approach allows for a much broader and more systematic understanding of reaction scope and trends. >
To overcome these limitations, the research team developed a 19F NMR-based multi-substrate simultaneous screening technology. This method involves performing asymmetric catalytic reactions with multiple reactants in a single reaction vessel, introducing a fluorine functional group into the products, and then applying their self-developed chiral cobalt reagent to clearly quantify all optical isomers using 19F NMR.
Utilizing the excellent resolution and sensitivity of 19F NMR, the research team successfully performed asymmetric synthesis reactions of 21 substrates simultaneously in a single reaction vessel and quantitatively measured the product yield and optical isomer ratio without any separate purification steps.
Professor Hyunwoo Kim stated, "While anyone can perform asymmetric synthesis reactions with multiple substrates in one reactor, accurately analyzing all the products has been a challenging problem to solve until now. We expect that achieving world-class multi-substrate screening analysis technology will greatly contribute to enhancing the analytical capabilities of AI-driven autonomous synthesis platforms."
< Figure 2. A method for analyzing multi-substrate asymmetric catalytic reactions, where different substrates react simultaneously in a single reactor, using fluorine nuclear magnetic resonance has been implemented. By utilizing the characteristics of fluorine nuclear magnetic resonance, which has a clean background signal and a wide chemical shift range, the reactivity of each substrate can be quantitatively analyzed. It is also shown that the optical activity of all reactants can be simultaneously measured using a cobalt metal complex. >
He further added, "This research provides a technology that can rapidly verify the efficiency and selectivity of asymmetric catalytic reactions essential for new drug development, and it is expected to be utilized as a core analytical tool for AI-driven autonomous research."
< Figure 3. It can be seen that in a multi-substrate reductive amination reaction using a total of 21 substrates, the yield and optical activity of the reactants according to the catalyst system were simultaneously measured using a fluorine nuclear magnetic resonance-based analysis platform. The yield of each reactant is indicated by color saturation, and the optical activity by numbers. >
Donghun Kim (first author, Integrated M.S./Ph.D. program) and Gyeongseon Choi (second author, Integrated M.S./Ph.D. program) from the KAIST Department of Chemistry participated in this research. The study was published online in the Journal of the American Chemical Society on May 27, 2025.※ Paper Title: One-pot Multisubstrate Screening for Asymmetric Catalysis Enabled by 19F NMR-based Simultaneous Chiral Analysis※ DOI: 10.1021/jacs.5c03446
This research was supported by the National Research Foundation of Korea's Mid-Career Researcher Program, the Asymmetric Catalytic Reaction Design Center, and the KAIST KC30 Project.
< Figure 4. Conceptual diagram of performing multi-substrate screening reactions and utilizing fluorine nuclear magnetic resonance spectroscopy. >
“One Experiment Is All It Takes”: KAIST Team Revolutionizes Drug Interaction Testing, Replacing 60,000 Studies
A groundbreaking new method developed by researchers at KAIST and Chungnam National University could drastically streamline drug interaction testing — replacing dozens of traditional experiments with just one.
The research, led by Professor Jae Kyoung Kim of KAIST Department of Mathematical Sciences & IBS Biomedical Mathematics Group and Professor Sang Kyum Kim of Chungnam National University's College of Pharmacy, introduces a novel analysis technique called 50-BOA, published in Nature Communications on June 5, 2025.
< Photo 1. (From left) Professor Sang Kyum Kim (Chungnam National University College of Pharmacy, co-corresponding author), Dr. Yun Min Song (IBS Biomedical Mathematics Group, formerly KAIST Department of Mathematical Sciences, co-first author), undergraduate student Hyeong Jun Jang (KAIST, co-first author), Professor Jae Kyoung Kim (KAIST and IBS Biomedical Mathematics Group, co-corresponding author) (Top left in the bubble) Professor Hwi-yeol Yun (Chungnam National University College of Pharmacy, co-author) >
For decades, scientists have had to repeat drug inhibition experiments across a wide range of concentrations to estimate inhibition constants — a process seen in over 60,000 scientific publications. But the KAIST-led team discovered that a single, well-chosen inhibitor concentration can yield even more accurate results.
< Figure 1. Graphical summary of 50-BOA. 50-BOA improves the accuracy and efficiency of inhibition constant estimation by using only a single inhibitor concentration instead of the traditionally used method of employing multiple inhibitor concentrations. >
“This approach challenges long-standing assumptions in experimental pharmacology,” says Prof. Kim. “It shows how mathematics can fundamentally redesign life science experiments.”
By mathematically analyzing the sources of error in conventional methods, the team found that over half the data typically collected adds no value or even skews results. Their new method not only cuts experimental effort by over 75%, but also enhances reproducibility and accuracy.
To help researchers adopt the method quickly, the team developed a user-friendly tool that takes simple Excel files as input, now freely available on GitHub:
☞ https://github.com/Mathbiomed/50-BOA
< Figure 2. The MATLAB and R package of 50-BOA at GitHub >
The work holds promise for faster and more reliable drug development, especially in assessing potential interactions in combination therapies. The U.S. FDA already emphasizes the importance of accurate enzyme inhibition assessment during early-stage drug evaluation — and this method could soon become a new gold standard.
KAIST Turns an Unprecedented Idea into Reality: Quantum Computing with Magnets
What started as an idea under KAIST’s Global Singularity Research Project—"Can we build a quantum computer using magnets?"—has now become a scientific reality. A KAIST-led international research team has successfully demonstrated a core quantum computing technology using magnetic materials (ferromagnets) for the first time in the world.
KAIST (represented by President Kwang-Hyung Lee) announced on the 6th of May that a team led by Professor Kab-Jin Kim from the Department of Physics, in collaboration with the Argonne National Laboratory and the University of Illinois Urbana-Champaign (UIUC), has developed a “photon-magnon hybrid chip” and successfully implemented real-time, multi-pulse interference using magnetic materials—marking a global first.
< Photo 1. Dr. Moojune Song (left) and Professor Kab-Jin Kim (right) of KAIST Department of Physics >
In simple terms, the researchers developed a special chip that synchronizes light and internal magnetic vibrations (magnons), enabling the transmission of phase information between distant magnets. They succeeded in observing and controlling interference between multiple signals in real time. This marks the first experimental evidence that magnets can serve as key components in quantum computing, serving as a pivotal step toward magnet-based quantum platforms.
The N and S poles of a magnet stem from the spin of electrons inside atoms. When many atoms align, their collective spin vibrations create a quantum particle known as a “magnon.”
Magnons are especially promising because of their nonreciprocal nature—they can carry information in only one direction, which makes them suitable for quantum noise isolation in compact quantum chips. They can also couple with both light and microwaves, enabling the potential for long-distance quantum communication over tens of kilometers.
Moreover, using special materials like antiferromagnets could allow quantum computers to operate at terahertz (THz) frequencies, far surpassing today’s hardware limitations, and possibly enabling room-temperature quantum computing without the need for bulky cryogenic equipment.
To build such a system, however, one must be able to transmit, measure, and control the phase information of magnons—the starting point and propagation of their waveforms—in real time. This had not been achieved until now.
< Figure 1. Superconducting Circuit-Based Magnon-Photon Hybrid System. (a) Schematic diagram of the device. A NbN superconducting resonator circuit fabricated on a silicon substrate is coupled with spherical YIG magnets (250 μm diameter), and magnons are generated and measured in real-time via a vertical antenna. (b) Photograph of the actual device. The distance between the two YIG spheres is 12 mm, a distance at which they cannot influence each other without the superconducting circuit. >
Professor Kim’s team used two tiny magnetic spheres made of Yttrium Iron Garnet (YIG) placed 12 mm apart with a superconducting resonator in between—similar to those used in quantum processors by Google and IBM. They input pulses into one magnet and successfully observed lossless transmission of magnon vibrations to the second magnet via the superconducting circuit.
They confirmed that from single nanosecond pulses to four microwave pulses, the magnon vibrations maintained their phase information and demonstrated predictable constructive or destructive interference in real time—known as coherent interference.
By adjusting the pulse frequencies and their intervals, the researchers could also freely control the interference patterns of magnons, effectively showing for the first time that electrical signals can be used to manipulate magnonic quantum states.
This work demonstrated that quantum gate operations using multiple pulses—a fundamental technique in quantum information processing—can be implemented using a hybrid system of magnetic materials and superconducting circuits. This opens the door for the practical use of magnet-based quantum devices.
< Figure 2. Experimental Data. (a) Measurement results of magnon-magnon band anticrossing via continuous wave measurement, showing the formation of a strong coupling hybrid system. (b) Magnon pulse exchange oscillation phenomenon between YIG spheres upon single pulse application. It can be seen that magnon information is coherently transmitted at regular time intervals through the superconducting circuit. (c,d) Magnon interference phenomenon upon dual pulse application. The magnon information state can be arbitrarily controlled by adjusting the time interval and carrier frequency between pulses. >
Professor Kab-Jin Kim stated, “This project began with a bold, even unconventional idea proposed to the Global Singularity Research Program: ‘What if we could build a quantum computer with magnets?’ The journey has been fascinating, and this study not only opens a new field of quantum spintronics, but also marks a turning point in developing high-efficiency quantum information processing devices.”
The research was co-led by postdoctoral researcher Moojune Song (KAIST), Dr. Yi Li and Dr. Valentine Novosad from Argonne National Lab, and Prof. Axel Hoffmann’s team at UIUC. The results were published in Nature Communications on April 17 and npj Spintronics on April 1, 2025.
Paper 1: Single-shot magnon interference in a magnon-superconducting-resonator hybrid circuit, Nat. Commun. 16, 3649 (2025)
DOI: https://doi.org/10.1038/s41467-025-58482-2
Paper 2: Single-shot electrical detection of short-wavelength magnon pulse transmission in a magnonic ultra-thin-film waveguide, npj Spintronics 3, 12 (2025)
DOI: https://doi.org/10.1038/s44306-025-00072-5
The research was supported by KAIST’s Global Singularity Research Initiative, the National Research Foundation of Korea (including the Mid-Career Researcher, Leading Research Center, and Quantum Information Science Human Resource Development programs), and the U.S. Department of Energy.