http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Novel Trp-rich Model Antimicrobial Peptoid with Increased Protease Stability
방정규,Yong Hai Nan,Eun Kyu Lee,신송엽 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.9
In order to increase protease stability of a novel Trp-rich model antimicrobial peptide, K6L2W3 (KLWKKWKKWLKNH2)and investigate the effect of L-amino acid to peptoid residue conversion on biological functions, we synthesized its antimicrobial peptoid, k6l2w3. Peptoid k6l2w3 had similar bacterial selectivity compared to peptide K6L2W3. The bactericidal rate of k6l2w3 was somewhat slower than that of K6L2W3. Peptoid k6l2w3 exhibited very little dye leakage from bacterial outer-membrane mimicking PE/PG liposomes, as observed in K6L2W3, indicating that the major target site of K6L2W3 and k6l2w3 may be not the cell membrane but the cytoplasm of bacteria. Trypsin treatment of K6L2W3 completely abolished antimicrobial activities against Escherichia coli and Staphylococcus aureus. In contrast, the antimicrobial activity of k6l2w3 was completely preserved after trypsin treatment. Taken together, our results suggested that antimicrobial peptoid k6l2w3 can potentially serves as a promising therapeutic agent for the treatment of microbial infection.
신아름,이은정,김진경,방정규,김양미 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.9
The 43-residue defensin-like peptide coprisin, which is isolated from dung bettle, Copris tripartitus, is a potent antimicrobial peptide. In our previous work, we determined the tertiary structure of coprisin and found that alpha helical region of coprisin from residue 19 to residue 30 is important for its antimicrobial activities. Here, we designed cop12mer and cop9mer analogs of coprisin based on the tertiary structure of coprisin. To investigate the relationship between hydrophobicity and antimicrobial activities and develop the potent peptide antibiotics, we designed cop9mer-1 with substitution of His2 with Trp in cop9mer. The results showed that cop9mer-1 has higher toxicities as well as improved antimicrobial activities compared to cop9mer. In order to reduce the toxicity of cop9mer-1, we designed cop9mer-2 and cop9mer-3 with substitution of Cys3 with Lys or Ser. Substitution of Cys3 with these hydrophilic amino acids results in lower cytotoxicities compared to cop9mer-1. Cop9mer-2 with substitution of Cys3 with Lys in Cop9mer-1 showed high antibacterial activities against drug resistant bacteria without cytotoxicity. Antibiotic action of cop9mer-1 analog appears to involve permeabilization of the bacterial cell membrane while cop9mer-2 and cop9mer-3 may have different mechanism of action. These results imply that that optimum balance in hydrophobicity and hydrophilicity in these 9-meric peptides plays key roles in their antimicrobial activities as well as cytotoxicities.
Plk1-Targeted Small Molecule Inhibitors: Mo-lecular Basis for Their Potency and Specificity
Ravichandran N. Murugan,박정은,김은희,신송엽,정재준,Kyung S Lee,방정규 한국분자세포생물학회 2011 Molecules and cells Vol.32 No.3
Members of polo-like kinases (collectively, Plks) have been identified in various eukaryotic organisms and play pivotal roles in cell proliferation. They are characterized by the presence of a distinct region of homology in the C-terminal noncatalytic domain, called polo-box domain (PBD). Among them, Plk1 and its functional homologs in other organisms have been best characterized because of its strong association with tumorigenesis. Plk1 is overexpressed in a wide spectrum of cancers in humans, and is thought to be an attractive anti-cancer drug target. Plk1 offers, within one molecule, two functionally different drug targets with distinct properties-the N-terminal catalytic domain and the C-terminal PBD essential for targeting the catalytic activity of Plk1 to specific subcellular locations. In this review, we focused on discussing the recent development of small-molecule and phosphopeptide inhibitors for their potency and specificity against Plk1. Our effort in understanding the binding mode of various inhibitors to Plk1 PBD are also presented.
안미자,신송엽,김은주,강신원,김은희,류은경,정재준,Ravichandran N. Murugan,안용해,손호익,방정규 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.9
Antimicrobial peptides have recently gained the much attention because of their ability to make defense system from attacking bacterial infections. Drosocin has been considered as very attractive antibiotic agents because of low toxicity against human erythrocytes and active at the low concentration. We have studied the structureactivity relationship of a glycopeptide drosocin focused on the N-acetyl-D-galactoside at Thr^11 residue. Based on the radial diffusion assay, we found that the acetylation of carbohydrate moiety increased the antimicrobial activity and the Pro^10, present in the middle of drosocin plays an important role in the antimicrobial activity. Our results provide a good lead compound for further studies on the design of drosocin-based analogues targeting glyco linked Thr site.
Kim, Sung-Min,Naeun Choi,송영규,Gyunggoo Cho,방정규,Sang Mi Kim,이상훈,유은경 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.6
Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) have been implicated in the pathogenesis of rheumatoid arthritis, which is angiogenesis dependent. Antibody-based molecular imaging improves targeting, and antibody radiolabeling is useful for monitoring biological events in vivo via PET or SPECT. We investigated the potential of molecular imaging to diagnose arthritis with VEGFR-2 in vivo. The 123I-VEGFR- 2 antibody was prepared by the iodogen tube method. The radioligand was injected into arthritic mice, and micro SPECT/CT was performed. The arthritic mice were examined by 4.7-T MRI and immunohistochemistry. The 123I-VEGFR-2 antibody showed high uptake in the arthritic region at 1 h postinjection on SPECT/CT but no uptake in the control animals after radioligand injection. In MR images, the arthritic tissue of the mice was correlated with regions labeled by the 123I-VEGFR-2 antibody. Immunohistochemical localization showed markedly increased expression of VEGFR-2 in the endothelial cells, fibroblasts, and macrophages of the arthritic mice.
Kyung S Lee,Jung-Eun Park,Young Hwi Kang,김태성,방정규 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.4
Mammalian polo-like kinase 1 (Plk1) has been studied intensively as a key regulator of various cell cycle events that are critical for proper M-phase progression. The polo-box domain (PBD) present in Plk1’s C-terminal non-catalytic region has been shown to play a central role in targeting the N-terminal kinase domain of Plk1 to specific subcellular locations. Subsequent studies reveal that PBD binds to a phosphorylated motif generated by one of the two mechanisms - self-priming by Plk1 itself or non-self-priming by a Pro-directed kinase, such as Cdc2. Here, we comparatively review the differences in the biochemical steps of these mechanisms and discuss their physiological significance. Considering the diverse functions of Plk1 during the cell cycle, a better understanding of how the catalytic activity of Plk1 functions in concert with its cis-acting PBD and how this coordinated process is intricately regulated to promote Plk1 functions will be important for providing new insights into different mechanisms underlying various Plk1-mediated biological events that occur at the multiple stages of the cell cycle.
다목적 가속기 구축을 위한 전자 맴돌이 공명 이온원 개념 설계
이병섭(B.S. Lee),원미숙(M.S. Won),김종필(J.P. Kim),윤장희(J.H. Yoon),배종성(J.S. Bae),방정규(J.K. Bang),안정근(J.K. Ahn) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
The construction of a multi-purpose linear accelerator IS ill progress by Korea Basic Science Institute. The main capability of this facility is the production of multiply ionized metal clusters and the generation more intense beams of highly charged ions for material, medical and nuclear physical research. To produce the intense beam of highly charged ions, we will construct an Electron Cyclotron Resonance Ion Source(ECRIS) using 28㎓ microwaves. For this ECRIS, The development of a conduction-cooled superconducting magnet will complete in this year. In this paper, we are introduced multi-purpose accelerator project and conceptual design of ECRIS.