2021학년도 자연과학대학 학부생 동계 인턴십 신청 안내(~11.19) *안내페이지로 가기 : 팝업창 클릭
입학 및 졸업 관련양식
연구비 및 여행관련양식
Building on Tradition
Soaring into the Future
SNU Department of Chemistry
Integrating Research and Teaching
to Advance Frontiers in Chemistry
SNU Department of Chemistry
Department of Chemistry
Seoul National University
Creative, Collaborative, and Innovative
Seoul National University
서울대 화학부 이동환 교수 세상에서 가장 작은 발광체 발명
서울대 화학부 이동환 교수 연구진은 지금까지 알려진 분자 중에서 가장 크기가 작은 적색광 발광체를 발명하고, 긴 파장에서 빛이 나오는 광물리학적 메커니즘을 이론적으로 규명함으로써, 형광 분자의 새로운 설계 전략을 제시했다. 이 결과는 국제학술지인 Nature Communications에 9월 13일 온라인으로 발표되었다.
KAIST-서울대, 생체 내 특이적 분비단백질 표지기법 개발
공동연구팀은 근접 표지 효소를 활용해 생쥐의 혈장 내에서 특정 조직이 분비하는 단백질만을 분리할 수 있는 기법을 개발했다. 이러한 체내 표지 기법은 지금까지의 체외 세포주 실험의 한계를 뛰어넘어 질병과 관련된 바이오마커 및 치료 표적 발굴에 적용될 수 있을 것으로 기대된다.
박승범 교수 연구팀 퇴행성 뇌신경 질환 치료의 새로운 작용기전을 밝혀
치매 파킨슨병과 같은 퇴행성 뇌신경 질환의 병변중의 하나인 타우단백질의 응집을 저해하는 신규 약물 후보물질을 표현형 기반 스크리닝으로 발굴 세포내 작용기작을 밝히고 동물 모델에서 효능을 확인해 퇴행성 뇌질환 치료제 개발에 실마리를 얻었다.
수소기체 얻을 수 있는 물 전기분해 촉매 개발
물 전기분해를 통한 수소생산은 수소경제를 완성하기 위해 필수적이기 때문에 중요하게 인식되고 있다. 이에 연구팀은 이차전지 양극소재인 리튬 코발트 산화물(LiCoO2)에 염화이온(Cl-)을 미세하게 도핑하는 방법으로 경제성, 효율성, 수명을 현저히 향상시킨 물 전기분해 양(+)극 촉매를 개발했다.
한국연구재단 "서울대, 생합성 모사한 비타민B3 합성법 개발"
지질대사에 필수적인 비타민 B3가 포함된 다양한 저분자 물질을 단일반응으로 얻을 수 있는 합성법이 소개됐다. 이는 다양한 생리활성 분자를 설계할 수 있는 실마리가 될 것으로 기대된다.
'껌만 씹어도 배부른 이유' 찾았다
19세기 중반부터 20세기 중반까지 생리학자들은 동물의 소화관에 구멍을 내서 물이 위에서 새어나가게 하거나 위에 풍선을 넣고 바람을 불어넣어 부풀린 뒤 먹이를 먹게 하는 실험을 진행했다.
지구온난화로 인한 이상 고온 대응 식물 생존 원리 발견
최근 이상 기온에 대응해 식물은 자체적으로 적극적인 방어 전략을 구축하고 능동적으로 적응함으로써 고온에서도 최적의 생장을 유지하고 나아가 고온에 의한 세포 피해나 식물 자체가 고사하는 상황을 효율적으로 극복하는 분자적 원리를 세계 최초로 증명했다.
장내 병원균의 감염에 필수적인 단백질의 구조 규명
서울대학교와 노트르담대학교 국제공동연구팀이 '장내 병원균 감염에 필수적인 단백질 구조'를 규명했다.
공지사항 / 세미나
학내 사이버 보안 강화 안내
2021학년도 동계 계절수업 강원대학교 교류수학 안내[혁신공유대학 에너지신산업 분야]
2021 제3회 KOREA DATA-BIZ TRENDS 행사 안내
2021학년도 동계 계절수업 교양 교과목 성적평가방법 변경 안내
특별세미나 - Prof. Stephen D. Liberles (Harvard Medical School)
Neuronal mechanisms of interoception
정규세미나 - 이윤미 교수 (연세대학교 화학과)
Main Group Catalysis for Selective Chemical Synthesis: Synthetic and Mechanistic Studies
특별세미나 - Prof. Yifan Cheng (UCSF)
Structural biology in the era of AlphaFold - capturing structural snapshots to dissect functional dynamics
특별세미나 - Prof. Chi-Ming Che, Prof. Lutz H. Gade, Prof. Christian Limberg, Prof. Cho Jaeheung, Prof. Marc-Etienne, Prof. Didier Bourissou (University of Hong Kong, University of Heidelberg, Humboldt-Universität zu Berlin, University of Utrecht, University of Toulouse, UNIST, Seoul National University)
THE 1ST SNU INTERNATIONAL ORGANOMETALLIC CHEMISTRY SYMPOSIUM
정규세미나 - 이한주 교수 (한국기초과학연구원(KBSI))
Label-free vibrational imaging of microplastic in biological system
특별세미나 - Prof. Diego Bohórquez (Duke University)
Sugar: A gut choice
Strain-Induced Modulation of Localized Surface Plasmon Resonance in Ultrathin Hexagonal Gold Nanoplates
Anisotropic gold nanoplates (NPLs) have raised the interesting possibility that their reduced geometrical symmetry allows fine tuning of their optical properties associated with the excitation of localized surface plasmon resonances (LSPRs). Recent developments have greatly improved LSPR tunability by utilizing the spatial distribution of LSPR modes. However, the nanoscale interplay between defect-induced mechanical strain and the spatial variation of LSPR modes remains poorly understood. In this work, the combination of high spatial- and spectral-resolution mapping of LSPR modes and nanoscale strain mapping using aberration-corrected transmission electron microscopy are applied to investigate the nanoscale distribution of LSPR modes in an ultrathin single hexagonal gold NPL and the effect of defect-induced strains on its LSPR properties. The electron energy-loss spectral maps reveal four distinct LSPR components and intensity distributions of all LSPR modes in a hexagonal gold NPL. Furthermore, the strain maps provide experimental evidence that the tensile strain field induced by a Z-shaped faulted dipole is responsible for the asymmetric distribution of LSPR intensity in a hexagonal gold NPL.
Hydrothermally obtained type-Ⅱ heterojunction nanostructures of In2S3 / TiO2 for remarkably enhanced photoelectrochemical water splitting
Despite the tremendous attempts to improve the solar-to-hydrogen conversion efficiency of TiO2 based photoelectrochemical photoanode, further progress is still needed to utilize the TiO2 as the promising photoanode materials. Herein, a highly enhanced photoanode composed of the nanostructured In2S3/TiO2 is synthesized. The photocurrent density approximately 3.5 times (2.74 mA cm−2) as high as the pristine TiO2 was obtained due to the improved carrier concentration and fast charge separation. The incident photon-to-current efficiency shows a 65.8 % while pristine TiO2 nanorods shows only 24.7 % of efficiency. Further studies on the carrier lifetime and band position were performed and clarify the generation of type-Ⅱ heterojunction between the In2S3 nanoparticles and TiO2 nanorod arrays. This study proposes the methodologies and the theoretical evidence for achieving significant improvements in the TiO2 based photoanode. Moreover, this study's all-solution-based process provides the facile and scalable method for the highly enhanced photoelectrode and allows environmentally friendly production.
Design of artificial metalloenzymes with multiple inorganic elements: The more the merrier
A large fraction of metalloenzymes harbors multiple metal-centers that are electronically and/or functionally arranged within their proteinaceous environments. To explore the orchestration of inorganic and biochemical components and to develop bioinorganic catalysts and materials, we have described selected examples of artificial metalloproteins having multiple metallocofactors that were grouped depending on their initial protein scaffolds, the nature of introduced inorganic moieties, and the method used to propagate the number of metal ions within a protein. They demonstrated that diverse inorganic moieties can be selectively grafted and modulated in protein environments, providing a retrosynthetic bottom-up approach in the design of versatile and proficient biocatalysts and biomimetic model systems to explore fundamental questions in bioinorganic chemistry.
3D Microfluidic Platform and Tumor Vascular Mapping for Evaluating Anti-Angiogenic RNAi-Based Nanomedicine
Three-dimensional (3D) visualization of tumor vasculature is a key factor in accurate evaluation of RNA interference (RNAi)-based antiangiogenic nanomedicine, a promising approach for cancer therapeutics. However, this remains challenging because there is not a physiologically relevant in vitro model or precise analytic methodology. To address this limitation, a strategy based on 3D microfluidic angiogenesis-on-a-chip and 3D tumor vascular mapping was developed for evaluating RNAi-based antiangiogenic nanomedicine. We developed a microfluidic model to recapitulate functional 3D angiogenic sprouting when co-cultured with various cancer cell types. This model enabled efficient and rapid assessment of antiangiogenic nanomedicine in treatment of hyper-angiogenic cancer. In addition, tissue-clearing-based whole vascular mapping of tumor xenograft allowed extraction of complex 3D morphological information in diverse quantitative parameters. Using this 3D imaging-based analysis, we observed tumor sub-regional differences in the antiangiogenic effect. Our systematic strategy can help in narrowing down the promising targets of antiangiogenic nanomedicine and then enables deep analysis of complex morphological changes in tumor vasculature, providing a powerful platform for the development of safe and effective nanomedicine for cancer therapeutics.
Quantitative assessment of engineered Cas9 variants for target specificity enhancement by single-molecule reaction pathway analysis
There have been many engineered Cas9 variants that were developed to minimize unintended cleavage of off-target DNAs, but detailed mechanism for the way they regulate the target specificity through DNA:RNA heteroduplexation remains poorly understood. We used single-molecule FRET assay to follow the dynamics of DNA:RNA heteroduplexation for various engineered Cas9 variants with respect to on-target and off-target DNAs. Just like wild-type Cas9, these engineered Cas9 variants exhibit a strong correlation between their conformational structure and nuclease activity. Compared with wild-type Cas9, the fraction of the cleavage-competent state dropped more rapidly with increasing base-pair mismatch, which gives rise to their enhanced target specificity. We proposed a reaction model to quantitatively analyze the degree of off-target discrimination during the successive process of R-loop expansion. We found that the critical specificity enhancement step is activated during DNA:RNA heteroduplexation for evoCas9 and HypaCas9, while it occurs in the post-heteroduplexation stage for Cas9-HF1, eCas9, and Sniper-Cas9. This study sheds new light on the conformational dynamics behind the target specificity of Cas9, which will help strengthen its rational designing principles in the future.
Highly Stable Si MOSFET-type Humidity Sensor with Ink-jet Printed Graphene Quantum Dots Sensing Layer
This paper investigates humidity sensing characteristics of a silicon metal oxide semiconductor field effect transistor (Si MOSFET)-based humidity sensor having horizontal floating-gate (FG) interdigitated with control-gate (CG). The sensing material of the humidity sensor is graphene quantum dots (GQDs), deposited locally on the interdigitated CG-FG area by an ink-jet printing method using a small amount of the GQDs solution. The humidity sensing characteristics of the sensor are measured as a parameter of relative humidity (RH). The response of the humidity sensor is 78 % to the humid air of 81.3 % RH. We also adopt a pulsed pre-bias method to improve the response and recovery characteristics of the humidity sensor. The response and recovery characteristics of the sensor can be improved 30 % and 40 % respectively by applying a pre-bias of 2 V and -1 V to the CG. In all relative humidity ranges, the FET-type humidity sensor has highly stable and reproducible characteristics in long-term measurements for 5 months.
Iridium(Ⅲ) complex-based phosphorescent and electrochemiluminescent dual sensor for selective detection of glutathione
Glutathione (GSH) is the most abundant biological thiol and involved in antioxidant defense systems in human cells. Lack of GSH increases the risk of oxidative stress, resulting in the progression of cancer. Therefore, a selective detection method for GSH is highly required. Herein, we report phosphorescent and electrochemiluminescent dual sensors (1-3) based on iridium complexes for the selective detection of GSH. These sensors have a 1,10-phenanthroline-5,6-dione (pdo) ancillary ligand as a common reaction site for GSH. Reduction of the pdo moiety to 1,10-phenanthroline-5,6-diol (phen(OH)2) upon reaction of sensors with GSH triggered fluorescence turn-on response and electrochemiluminescence turn-off response with high selectivity for GSH. Sensing mechanisms were elucidated by DFT calculations and cyclic voltammetry. Sensor 1 was successfully applied to determination of GSH concentrations in human serum samples by ECL methods.
SuFEx-Click Approach for the Synthesis of Soluble Polymer-Bound MacMillan Catalysts for the Asymmetric Diels–Alder Reaction
Novel polymeric MacMillan catalysts were prepared from modified chiral imidazolidin-4-one monomers via sulfur(VI) fluoride exchange chemistry. The resulting polysulfates containing chiral imidazolidin-4-one units could be employed as polymeric organocatalysts for the asymmetric Diels–Alder reaction. With the use of these polysulfate catalysts, sufficient catalytic activity and enantioselectivity were obtained, which were similar to those obtained by monomeric catalysts in a homogeneous catalytic reaction. In addition, the polysulfate catalysts could be recovered and reused five times without a considerable loss of activity and selectivity.
Mechanism of Cyanine5 to Cyanine3 Photoconversion and Its Application for High-Density Single-Particle Tracking in a Living Cell
Cyanine (Cy) dyes are among the most useful organic fluorophores that have found a wide range of applications in single-molecule and super-resolution imaging as well as in other biophysical studies. However, recent observations that blueshifted derivatives of Cy dyes are formed via photoconversion have raised concerns as to the potential artifacts in multicolor imaging. Here, we report the mechanism for the photoconversion of Cy5 to Cy3 that occurs upon photoexcitation during fluorescent imaging. Our studies show that the formal C2H2 excision from Cy5 occurs mainly through an intermolecular pathway involving a combination of bond cleavage and reconstitution while unambiguously confirming the identity of the fluorescent photoproduct of Cy5 to be Cy3 using various spectroscopic tools. The carbonyl products generated from singlet oxygen-mediated photooxidation of Cy5 undergo a sequence of carbon–carbon bond-breaking and -forming events to bring about the novel dye-to-dye transformation. We also show that the deletion of a two-methine unit from the polymethine chain, which results in the formation of blueshifted products, commonly occurs in other cyanine dyes, such as Alexa Fluor 647 (AF647) and Cyanine5.5. The formation of a blueshifted congener dye can obscure the multicolor fluorescence imaging, leading to misinterpretation of the data. We demonstrate that the potentially deleterious photoconversion, however, can be exploited to develop a new photoactivation method for high-density single-particle tracking in a living cell without using UV illumination and cell-toxic additives.
Safeguarding genome integrity under heat stress in plants
Heat stress adversely affects an array of molecular and cellular events in plant cells, such as denaturation of protein and lipid molecules and malformation of cellular membranes and cytoskeleton networks. Genome organization and DNA integrity are also disturbed under heat stress, and accordingly, plants have evolved sophisticated adaptive mechanisms that either protect their genomes from deleterious heat-induced damages or stimulate genome restoration responses. In particular, it is emerging that DNA damage responses are a critical defense process that underlies the acquirement of thermotolerance in plants, during which molecular players constituting the DNA repair machinery are rapidly activated. In recent years, thermotolerance genes that mediate the maintenance of genome integrity or trigger DNA repair responses have been functionally characterized in various plant species. Furthermore, accumulating evidence supports that genome integrity is safeguarded through multiple layers of thermoinduced protection routes in plant cells, including transcriptome adjustment, orchestration of RNA metabolism, protein homeostasis, and chromatin reorganization. In this review, we summarize topical progresses and research trends in understanding how plants cope with heat stress to secure genome intactness. We focus on molecular regulatory mechanisms by which plant genomes are secured against the DNA-damaging effects of heat stress and DNA damages are effectively repaired. We will also explore the practical interface between heat stress response and securing genome integrity in view of developing biotechnological ways of improving thermotolerance in crop species under global climate changes, a worldwide ecological concern in agriculture.
입학 및 졸업 관련양식
연구비 및 여행관련양식