Mechanisms of antimicrobial, cytolytic, and cell-penetrating peptides: from kinetics to thermodynamics.
The mechanisms of six different antimicrobial, cytolytic, and cell-penetrating peptides, including some of their variants, are discussed and compared. The specificity of these polypeptides varies; however, they all form amphipathic alpha-helices when bound to membranes, and there are no striking differences in their sequences. We have examined the thermodynamics and kinetics of their interaction with phospholipid vesicles, namely, binding and peptide-induced dye efflux. The thermodynamics of binding calculated using the Wimley-White interfacial hydrophobicity scale are in good agreement with the values derived from experiment. The generally accepted view that binding affinity determines functional specificity is also supported by experiments in model membranes. We now propose the hypothesis that it is the thermodynamics of the insertion of the peptide into the membrane, from a surface-bound state, that determine the mechanism.
Almeida
Paulo F
PF
Department of Chemistry and Biochemistry, University of North Carolina Wilmington, North Carolina 28403, USA. almeidap@uncw.edu
Pokorny
Antje
A
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002477:Cells / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D021381:Protein Transport; D013816:Thermodynamics
D023181:Antimicrobial Cationic Peptides