Alyteserin-2a – Antimicrobial Peptides – AMP

Alyerserin-2a is a C-terminally α-amidated 17 residue cationic anti-microbial peptide (AMP). Anti-microbial peptides (AMPs) are produced by the innate immune system and are expressed when the host is challenged by a pathogen. The Alyerserin family of peptides was first identified in norepinephrine-stimulated skin secretions of the midwife toad-Alytes obstetricans-(Alytidae). Alyteserin-2a, 2b and -2c show some sequence identity with bombinin H6, a peptide from the skins Bombinatoridae family of frogs. Alyteserin-2a is most potent against the Gram-positive bacteria-Staphylococcus aureus and has weak haemolytic activity against human erythrocytes. Alyteserin contain at least 50% hydrophobic amino acids. Hydrophobic residues contribute to the insertion of the peptide into the hydrophobic membrane core which results in membrane disruption and death of the pathogen. Due to their mechanism of action it is thought to be less likely for resistance to develop towards them compared to conventional antibiotics. Alyteserin-2a has the tendency to adopt an α-helical conformation between residues 9-14 when in membrane-mimetic solvent.