Premium
Plasticity in structure and interactions is critical for the action of indolicidin, an antibacterial peptide of innate immune origin
Author(s) -
Nagpal Sushma,
Kaur Kanwal J.,
Jain Deepti,
Salunke Dinakar M.
Publication year - 2002
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.0211602
Subject(s) - cathelicidin , peptide , biology , innate immune system , biochemistry , peptide sequence , antibacterial activity , protein structure , antimicrobial peptides , biophysics , bacteria , genetics , receptor , gene
The comparative analysis of two cationic antibacterial peptides of the cathelicidin family—indolicidin and tritrypticin—enabled addressing the structural features critical for the mechanism of indolicidin activity. Functional behavior of retro‐indolicidin was found to be identical to that of native indolicidin. It is apparent that the gross conformational propensities associated with retro‐peptides resemble those of the native sequences, suggesting that native and retro‐peptides can have similar structures. Both the native and the retro‐indolicidin show identical affinities while binding to endotoxin, the initial event associated with the antibacterial activity of cationic peptide antibiotics. The indolicidin–endotoxin binding was modeled by docking the indolicidin molecule in the endotoxin structure. The conformational flexibility associated with the indolicidin residues, as well as that of the fatty acid chains of endotoxin combined with the relatively strong structural interactions, such as ionic and hydrophobic, provide the basis for the endotoxin–peptide recognition. Thus, the key feature of the recognition between the cationic antibacterial peptides and endotoxin is the plasticity of molecular interactions, which may have been designed for the purpose of maintaining activity against a broad range of organisms, a hallmark of primitive host defense.