• 제목/요약/키워드: single molecule

검색결과 349건 처리시간 0.03초

Biosynthesis of a Biological Active Single Chain Equine Chorionic Gonado-tropin

  • Min, Kwan-Sik
    • Journal of Life Science
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    • 제11권2호
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    • pp.103-107
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    • 2001
  • The equine chorionic gonadotropin (eCG) subunits $\alpha$ and ${\beta}$ are transcribed from different genes and associate noncovalently to form the bioactive eCG heterodimer. Dimerization is rate limiting for eCG secretion, and dissociation leads to hormone inactivation. The correct conformation of the heterodimer is alto important for efficient secretion, hormone-specific post-translational modifications, receptor binding and signal transduction. To determine whether ${\alpha}$ and ${\beta}$ subunits can be synthesized as a single polypeptide chain (tethered-eCG) and also display biological activity, the tethered-eCG molecule by fusing the carboxyl terminus of the eCG ${\beta}$-subunit to the amino terminus of the af-subunit was construe-ted and transfected into chinese hamster ovary (CHO-Kl) cells. LH- and FSH-like activities were assayed in terms of testosterone production and aromatase activity in primary cultured rat Leydig cells and granulosa cells, respectively. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG ${\alpha}$/${\beta}$ and native eCG. FSH-like activity of the tethered-eCG was also shown similarly in comparison with the native and wild type eCG ${\alpha}$/${\beta}$. Our data for the first time suggest that the tethered-eCG can be expressed efficiently and the produced product by the CHO-K1 cells is fully LH- and FSH-like activities in rat in vitro bioassay system. Our results also suggest that this molecular can imply particular models of FSH-like activity not LH-like activity in the eCG. Taken together, these data indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion.

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Characterization of the Rosellinia necatrix Transcriptome and Genes Related to Pathogenesis by Single-Molecule mRNA Sequencing

  • Kim, Hyeongmin;Lee, Seung Jae;Jo, Ick-Hyun;Lee, Jinsu;Bae, Wonsil;Kim, Hyemin;Won, Kyungho;Hyun, Tae Kyung;Ryu, Hojin
    • The Plant Pathology Journal
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    • 제33권4호
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    • pp.362-369
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    • 2017
  • White root rot disease, caused by the pathogen Rosellinia necatrix, is one of the world's most devastating plant fungal diseases and affects several commercially important species of fruit trees and crops. Recent global outbreaks of R. necatrix and advances in molecular techniques have both increased interest in this pathogen. However, the lack of information regarding the genomic structure and transcriptome of R. necatrix has been a barrier to the progress of functional genomic research and the control of this harmful pathogen. Here, we identified 10,616 novel full-length transcripts from the filamentous hyphal tissue of R. necatrix (KACC 40445 strain) using PacBio single-molecule sequencing technology. After annotation of the unigene sets, we selected 14 cell cycle-related genes, which are likely either positively or negatively involved in hyphal growth by cell cycle control. The expression of the selected genes was further compared between two strains that displayed different growth rates on nutritional media. Furthermore, we predicted pathogen-related effector genes and cell wall-degrading enzymes from the annotated gene sets. These results provide the most comprehensive transcriptomal resources for R. necatrix, and could facilitate functional genomics and further analyses of this important phytopathogen.

MicroRNA super-resolution imaging in blood for Alzheimer's disease

  • Mirae Lee;Jiwon Woo;Sang Tae Kim;Minho Moon;Sang Yun Kim;Hanna Cho;Sujin Kim;Han-Kyeol Kim;Jeong-Yoon Park
    • BMB Reports
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    • 제56권3호
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    • pp.190-195
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    • 2023
  • We propose a novel blood biomarker detection method that uses miRNA super-resolution imaging to enable the early diagnosis of Alzheimer's disease (AD). Here, we report a single-molecule detection method for visualizing disease-specific miRNA in tissue from an AD mice model, and peripheral blood mononuclear cells (PBMCs) from AD patients. Using optimized Magnified Analysis of Proteome (MAPs), we confirmed that five miRNAs contribute to neurodegenerative disease in the brain hippocampi of 5XFAD and wild-type mice. We also assessed PBMCs isolated from the whole blood of AD patients and a healthy control group, and subsequently analyzed those samples using miRNA super-resolution imaging. We detected more miR-200a-3p expression in the cornu ammonis 1 and dentate gyrus regions of 3 month-old 5XFAD mice than in wild-type mice. Additionally, miRNA super-resolution imaging of blood provides AD diagnosis platform for studying miRNA regulation inside cells at the single molecule level. Our results present a potential liquid biopsy method that could improve the diagnosis of early stage AD and other diseases.

One-dimensional Nanomaterials for Field Effect Transistor (FET) Type Biosensor Applications

  • Lee, Min-Gun;Lucero, Antonio;Kim, Ji-Young
    • Transactions on Electrical and Electronic Materials
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    • 제13권4호
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    • pp.165-170
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    • 2012
  • One-dimensional, nanomaterial field effect transistors (FET) are promising sensors for bio-molecule detection applications. In this paper, we review fabrication and characteristics of 1-D nanomaterial FET type biosensors. Materials such as single wall carbon nanotubes, Si nanowires, metal oxide nanowires and nanotubes, and conducting polymer nanowires have been widely investigated for biosensors, because of their high sensitivity to bio-substances, with some capable of detecting a single biomolecule. In particular, we focus on three important aspects of biosensors: alignment of nanomaterials for biosensors, surface modification of the nanostructures, and electrical detection mechanism of the 1-D nanomaterial sensors.

Nanoparticle plasmonics: from single molecule chemistry to materials science

  • 김지환
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.76.2-76.2
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    • 2015
  • I will present my research group's recent investigation on how the localized plasmon of a nanoparticle interacts with another plasmon, and with nearby molecules. First, I will demonstrate the use of scattering-type scanning near-field microscopy (s-SNOM) to directly visualize the capacitive / conductive coupling in dimeric nanoparticles and heterometallic nanorods. Second, I will talk about the use of gap-plasmons to locally induce photochemical reactions, and to follow chemical kinetics of individual organic molecules using the gap-plasmons. As a last topic, I will talk about the use of near-field coupling between a scanning probe and graphenes to visualize / identify the stacking domains (e. g., ABA versus ABC-type stacking in triple layer) hidden in multilayer graphenes.

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색소 농도에 따른 형광 광자의 계수율 : 광자 검출기의 dead time 효과 (Fluorescence photon counting rate as a function of dye concentration: Effect of dead time of photon detector)

  • 고동섭
    • 한국광학회지
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    • 제8권4호
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    • pp.353-355
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    • 1997
  • 공초점 형광 현미경과 단일 광자 계수기로 구성되어 있는 단일 분자 검출장치를 사용하여, 색소 농도에 따른 광자 계수율의 변화를 관측하였다. 농도가 증가함에 따라 계수율이 포화하는 경향을 보였으며, 광검출기의 죽은 시간을 고려하여 측정 결과를 설명하였다. 계수율과 검출 부피, 광검출기의 양자효율, 입사 광량 사이의 관계를 나타내는 관계식을 제시하였다. 또한 신호대 잡음비에 대해서도 간략하게 논하였다.

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Biological Function of Single Chain Equine Chorionic Gonadotiopin Mutants(C-terminal Deletions)

  • 정윤희;박종주;김민수;이유연;;윤종택;민관식
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.210-210
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    • 2004
  • Equinechorionic gonadotropin(eCG) is a member of the glycoprotein hormone family which includes FSH, hCG, TSH. These hormone family is characterized by a heterodimeric structure composed a common α-subunit noncovalently linked to a hormone specific β-subunit. To determine a and β-subunits can be synthesized as a single polypeptide chain (tethered-eCG) and also display biological activity, the tethered-molecule by fusing the carboxyl terminus of the eCG β-subunit to the amino terminus of the α-subunit was constructed and transfected into chinese hamster ovary (CHO-K1) cells. (omitted)

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Nanoscale-NMR with Nitrogen Vacancy center spins in diamond

  • Lee, Junghyun
    • 한국자기공명학회논문지
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    • 제24권2호
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    • pp.59-65
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    • 2020
  • Nitrogen-Vacancy (NV) center in diamond has been an emerging versatile tool for quantum sensing applications. Amongst various applications, nano-scale nuclear magnetic resonance (NMR) using a single or ensemble NV centers has demonstrated promising results, opening possibility of a single molecule NMR for its chemical structural studies or multi-nuclear spin spectroscopy for quantum information science. However, there is a key challenge, which limited the spectral resolution of NMR detection using NV centers; the interrogation duration for NV-NMR detection technique has been limited by the NV sensor spin lifetime (T1 ~ 3ms), which is orders of magnitude shorter than the coherence times of nuclear spins in bulk liquid samples (T2 ~ 1s) or intrinsic 13C nuclear spins in diamond. Recent studies have shown that quantum memory technique or synchronized readout detection technique can further narrow down the spectral linewidth of NMR signal. In this short review paper, we overview basic concepts of nanoscale NMR using NV centers, and introduce further developments in high spectral resolution NV NMR studies.

Stability and Electronic Properties of the Adsorption of Molecular Hydrogen on Metal-containing Single-walled Carbon Nanotubes

  • Michael, Mananghaya
    • 대한화학회지
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    • 제59권5호
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    • pp.429-433
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    • 2015
  • The binding ability and hydrogen storage capacity of nitrogen doped carbon nanotube with divacancy (4NDCNxNT) that is decorated with transition metals was investigated based on density functional theory calculations. Results indicate that scandium shows an ideal reversible hydrogen binding capability with promising system-weight efficiency compared with other transition metals when functionalized with 4ND-CNxNT. The (Sc/4ND)10-CNxNT can store up to 50H2 molecules, corresponding to a maximum gravimetric density of 5.8 wt%. Detailed structural stability and electronic properties were reported as hydrogen molecules were absorbed. It takes about 0.16 eV/H2 to add one H2 molecule, which assures reversible storage of H2 molecules under ambient conditions.

의약품의 손대칭성과 생리 활성 (Chirality of Drug Molecules and Biological Activity)

  • 권순경
    • Biomolecules & Therapeutics
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    • 제4권3호
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    • pp.209-223
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    • 1996
  • Chirality is important in the context of biological activity because at a molecular level, asymmetry dominates biological process. While most pharmaceuticals of natural origin are single enantiomers, most of the synthesized chiral drugs are used in the form of racemic mixtures of two or more diastereomers. The enantiomers of a racemic drug generally differ in pharmacodynamic and pharmacokinetic properties as a consequence of stereoselective interaction with optically active molecular components of living organism. In pharmacokinetics and pharmacodynamics enantioselectivity plays an important role. The information on the sum of eutomer and distorter in a racemic drugs is very important in the estimation of therapeutic advantage and/or toxicity of racemates. The choice of preferentially developing a single enantiomer should be based on actual therapeutic advantages and especially improved safety.

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