|Title||An acidic model pro-peptide affects the secondary structure, membrane interactions and antimicrobial activity of a crotalicidin fragment|
|Author(s)||Júnior, Nelson G.O.; Cardoso, Marlon H.; Cândido, Elizabete S.; Broek, Danielle van den; Lange, Niek de; Velikova, Nadya; Kleijn, J.M.; Wells, Jerry M.; Rezende, Taia M.B.; Franco, Octávio Luiz; Vries, Renko de|
|Source||Scientific Reports 8 (2018)1. - ISSN 2045-2322|
Physical Chemistry and Soft Matter
|Publication type||Refereed Article in a scientific journal|
In order to study how acidic pro-peptides inhibit the antimicrobial activity of antimicrobial peptides, we introduce a simple model system, consisting of a 19 amino-acid long antimicrobial peptide, and an N-terminally attached, 10 amino-acid long acidic model pro-peptide. The antimicrobial peptide is a fragment of the crotalicidin peptide, a member of the cathelidin family, from rattlesnake venom. The model pro-peptide is a deca (glutamic acid). Attachment of the model pro-peptide only leads to a moderately large reduction in the binding to- and induced leakage of model liposomes, while the antimicrobial activity of the crotalicidin fragment is completely inhibited by attaching the model pro-peptide. Attaching the pro-peptide induces a conformational change to a more helical conformation, while there are no signs of intra- or intermolecular peptide complexation. We conclude that inhibition of antimicrobial activity by the model pro-peptide might be related to a conformational change induced by the pro-peptide domain, and that additional effects beyond induced changes in membrane activity must also be involved.