A Study on the Importance of Phenylalanine for Aurein Functionality
Abstract:Aurein 2.5 (GLFDIVKKVVGAFGSL-NH2) is an amphibian antimicrobial peptide. Here, characterisation studies showed the peptide to exhibit molecular areas at an air / water interface (1.77 - 3.1 nm2), which are in agreement with the adoption of α-helical structures. Lipid monolayer studies showed aurein 2.5 to induce maximal surface pressure changes of circa 7 mN m-1 in monolayers formed from phosphatidylglycerol (PG) and circa 6 mN m-1 in those formed from phosphatidylethanolamine (PE). These data indicate that the membrane interactions of the peptide are amphiphilicity driven with no apparent electrostatic requirement. Individually mutating the phenylalanine residues of aurein 2.5 to leucine had no major effect on the levels of PG and PE interactions, suggesting that these residues are not essential to the membrane interactions of the peptide, contrasting to other aureins where corresponding phenylalanine residues are required for efficient membrane interaction and antibacterial activity. This difference in the requirement is suggested to relate to the surface architecture as proposed by the concept of the molecular perturbation potential.
Document Type: Research Article
Publication date: December 1, 2009
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- Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.