title: Conformational study of melectin and antapin antimicrobial peptides in model membrane environments.
abstract: Antimicrobial peptides have long been considered as promising compounds against drug-resistant pathogens. In this work, we studied the secondary structure of antimicrobial peptides melectin and antapin using electronic (ECD) and vibrational circular dichroism (VCD) spectroscopies that are sensitive to peptide secondary structures. The results from quantitative ECD spectral evaluation by Dichroweb and CDNN program and from the qualitative evaluation of the VCD spectra were compared. The antimicrobial activity of the selected peptides depends on their ability to adopt an amphipathic α-helical conformation on the surface of the bacterial membrane. Hence, solutions of different zwitterionic and negatively charged liposomes and micelles were used to mimic the eukaryotic and bacterial biological membranes. The results show a significant content of α-helical conformation in the solutions of negatively charged liposomes mimicking the bacterial membrane, thus correlating with the antimicrobial activity of the studied peptides. On the other hand in the solutions of zwitterionic liposomes used as models of the eukaryotic membranes, the fraction of α-helical conformation was lower, which corresponds with their moderate hemolytic activity.
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Kocourková
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic.
authors.forename: Pavlína
authors.initials: P
authors.lastname: Novotná
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic.
authors.forename: Sabína
authors.initials: S
authors.lastname: Čujová
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Čeřovský
authors.affiliation: Department of Physics and Measurements, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic.
authors.forename: Marie
authors.initials: M
authors.lastname: Urbanová
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic. Electronic address: Vladimir.Setnicka@vscht.cz.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Setnička
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D002942:Circular Dichroism; D017666:Deuterium Oxide / Q000737:chemistry; D006461:Hemolysis / Q000187:drug effects; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes; D008823:Micelles; D008826:Microbial Sensitivity Tests; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012996:Solutions
chemical_list: D023181:Antimicrobial Cationic Peptides; D008051:Lipid Bilayers; D008081:Liposomes; D008823:Micelles; D012996:Solutions; C000627993:antapin; C534036:melectin; D012967:Sodium Dodecyl Sulfate; D017666:Deuterium Oxide
keywords: Antimicrobial peptides; Circular dichroism; Conformation; Infrared spectroscopy; Liposomes; Model membranes