Effects of Hydrophobic Amino Acid Substitutions on Antimicrobial Peptide Behavior.

摘要: Antimicrobial peptides (AMPs) are naturally occurring components of the immune system that act against bacteria in a variety organisms throughout evolutionary hierarchy. There have been many studies focused on activity AMPs using biophysical and microbiological techniques; however, clear predictive mechanism toward determining if peptide will exhibit antimicrobial is still elusive, addition to fact action has shown vary between peptides, targets, experimental conditions. Nonetheless, majority contain hydrophobic amino acids facilitate partitioning into bacterial membranes net cationic charge promote selective binding anionic surfaces over zwitterionic host cell surfaces. This study explores role C18G as model system. These changes were evaluated for effects activity, peptide-lipid interactions Trp fluorescence spectroscopy, secondary structure formation, membrane permeabilization. The results show while formation was not significantly impacted by substitutions, antibacterial lipid well correlated. variants containing Leu or Phe sole groups bound bilayers with highest affinity most effective at inhibiting growth. Peptides Ile exhibited intermediate behavior those Val α-aminoisobutyric acid (Aib) showed poor activity. Leu, Phe, demonstrated preference bilayers, exhibiting significant emission spectrum shifts upon binding. Similarly, greater ability disrupt vesicles membranes. In total, data indicate moieties AMP sequence play