2JOS

Solution structure of piscidin in presence of DPC micelles

2JOS の概要

• エントリーDOI: 10.2210/pdb2jos/pdb
• 分子名称: Moronecidin (1 entity in total)
• 機能のキーワード: piscidin, antimicrobial, amphipathic helix, micellar environment, antimicrobial protein
• 由来する生物種: Morone saxatilis (striped sea-bass)
• 細胞内の位置: Secreted: Q8UUG0
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 2579.08

構造登録者

Campagna, S.,Saint, N.,Molle, G.,Aumelas, A. (登録日: 2007-03-21, 公開日: 2007-04-03, 最終更新日: 2023-12-20)

主引用文献

Campagna, S.,Saint, N.,Molle, G.,Aumelas, A.
Structure and mechanism of action of the antimicrobial peptide piscidin
Biochemistry, 46:1771-1778, 2007

PubMed Abstract: Piscidin, an antibacterial peptide isolated from the mast cells of striped bass, has potent antimicrobial activity against a broad spectrum of pathogens in vitro. We investigated the mechanism of action of this 22-residue cationic peptide by carrying out structural studies and electrophysiological experiments in lipid bilayers. Circular dichroism experiments showed that piscidin was unstructured in water but had a high alpha-helix content in dodecylphosphocholine (DPC) micelles. 1H NMR data in water and TFE confirmed these results and demonstrated that the segment of residues 8-17 adopted an alpha-helical structure in a micellar environment. This molecule has a marked amphipathic character, due to well-defined hydrophobic and hydrophilic sectors. This structure is similar to those determined for other cationic peptides involved in permeabilization of the bacterial membrane. Multichannel experiments with piscidin incorporated into azolectin planar bilayers gave reproducible I-V curves at various peptide concentrations and unambiguously showed that this peptide permeabilized the membrane. This pore forming activity was confirmed by single-channel experiments, with well-defined ion channels obtained at different voltages. The characteristics of the ion channels (voltage dependence, only one or two states of conductance) clearly suggest that piscidin is more likely to permeabilize the membrane by toroidal pore formation rather than via the "barrel-stave" mechanism.

PubMed: 17253775
DOI: 10.1021/bi0620297

実験手法

SOLUTION NMR