SOLUTION STRUCTURE OF AN ANTIMICROBIAL PEPTIDE BUFORIN-II

The structure of 21-residue antimicrobial peptide buforin II has been determined by using NMR spectroscopy and restrained molecular dynamics . Buforin II adopts a flexible random structure in H2O. In trifluoroet hanol (TFE)/H2O (1:1, v/v) mixture, however, buforin II assumes a regu lar alpha-helix between residues Val(12) and Arg(20) and distorted hel ical structure between residues Gly(7) and Pro(11). The model structur e obtained shows an amphipathic character in the region from Arg(5) to the C-terminus, Lys(21). Like other known cationic antimicrobial pept ides, the amphipathic structure might be the key factor for antimicrob ial activity of buforin II.