The α-defensin salt-bridge induces backbone stability to facilitate folding and confer proteolytic resistance.

ABSTRACT: Salt-bridge interactions between acidic and basic amino acids contribute to the structural stability of proteins and to protein-protein interactions. A conserved salt-bridge is a canonical feature of the α-defensin antimicrobial peptide family, but the role of this common structural element has not been fully elucidated. We have investigated mouse Paneth cell α-defensincryptdin-4 (Crp4) and peptide variants with mutations at Arg7 or Glu15 residue positions to disrupt the salt-bridge and assess the consequences on Crp4 structure, function, and stability. NMR analyses showed that both (R7G)-Crp4 and (E15G)-Crp4 adopt native-like structures, evidence of fold plasticity that allows peptides to reshuffle side chains and stabilize the structure in the absence of the salt-bridge. In contrast, int

SUBMITTER: Andersson HS 

PROVIDER: S-EPMC4086743 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature