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Acid destabilization of a triple‐helical peptide model of the macrophage scavenger receptor
Author(s) -
Rajini Balakrishnan Anachi,
Donald L. Siegel,
Jean Baum,
Barbara Brodsky
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00738-u
Subject(s) - scavenger receptor , peptide , macrophage , chemistry , scavenger , receptor , biophysics , biochemistry , microbiology and biotechnology , biology , in vitro , radical , lipoprotein , cholesterol
Electrostatic interactions were studied in a triple‐helical peptide, (POG) 3 PKGQKGEKG(POG) 4 , which contains a lysine‐rich 9 residue sequence from the collagen‐like domain of the macrophage scavenger receptor (MSR). This peptide adopts a stable triple‐helical conformation only when the pH is higher than 4.5, corresponding to ionization of the Glu side chain. Modeling shows Glu forms ion pairs with one of the Lys residues, stabilizing the structure. Previously studied collagen‐like peptides show relatively small contributions of electrostatic interactions to stability. The large magnitude of the pH mediated structural changes seen for this peptide suggests that specific placement of charged residues in the triple‐helix conformation can generate strong electrostatic interactions.