Structural study of novel antimicrobial peptides, nigrocins, isolated from Rana nigromaculata

FEBS Letters

Park, Sang-Ho²  Ahn, Hee-Chul²  Lee, Bong-Jin²  Kim, Sunny S.¹  Kim, Sunkyu¹  Lee, Byeong Jae¹  Park, Sangho² 

[1] Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, South Korea;Research Institute of Pharmaceutical Science, College of Pharmacy, Seoul National University, Seoul 151-742, South Korea

关键词: Antimicrobial peptide;    Nuclear magnetic resonance;    Circular dichroism;    Solution structure;    CD;    circular dichroism;    CFU;    colony forming units;    DPC;    dodecylphosphocholine;    DQF-COSY;    double quantum filtered correlation spectroscopy;    NMR;    nuclear magnetic resonance;    NOE;    nuclear Overhauser effect;    NOESY;    nuclear Overhauser effect spectroscopy;    r.m.s.d.;    root mean square deviation;    SDS;    sodium dodecyl sulfate;    TFE;    2;    2;    2-trifluoroethanol;    TOCSY;    total correlation spectroscopy;   

DOI  :  10.1016/S0014-5793(01)02956-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Novel cationic antimicrobial peptides, named nigrocin 1 and 2, were isolated from the skin of Rana nigromaculata and their amino acid sequences were determined. These peptides manifested a broad spectrum of antimicrobial activity against various microorganisms with different specificity. By primary structural analysis, it was revealed that nigrocin 1 has high sequence homology with brevinin 2 but nigrocin 2 has low sequence homology with any other known antimicrobial peptides. To investigate the structure–activity relationship of nigrocin 2, which has a unique primary structure, circular dichroism (CD) and homonuclear nuclear magnetic resonance spectroscopy (NMR) studies were performed. CD investigation revealed that nigrocin 2 adopts mainly an α-helical structure in trifluoroethanol (TFE)/H₂O solution, sodium dodecyl sulfate (SDS) micelles, and dodecylphosphocholine micelles. The solution structures of nigrocin 2 in TFE/H₂O (1:1, v/v) solution and in SDS micelles were determined by homonuclear NMR. Nigrocin 2 consists of a typical amphipathic α-helix spanning residues 3–18 in both 50% TFE solution and SDS micelles. From the structural comparison of nigrocin 2 with other known antimicrobial peptides, nigrocin 2 could be classified into the family of antimicrobial peptides containing a single linear amphipathic α-helix that potentially disrupts membrane integrity, which would result in cell death.

【 授权许可】

Unknown