Characterization of the disulfide motif in BNBD-12, an antimicrobial beta-defensin peptide from bovine neutrophils.

摘要: BNBD-12, a prototype beta-defensin peptide from bovine neutrophils, was chosen for determination of the disulfide motif in this family tridisulfide antimicrobial peptides. Disulfide-containing fragments BNBD-12 were generated by incubation with trypsin, and amino acid composition one tryptic fragment allowed assignment three disulfides. The remaining two disulfides, contained 16-residue oligopeptide, characterized analysis single round Edman degradation which cleaved Cys-Cys bond present near carboxyl terminus BNBD-12. Cleavage produced disulfide-containing oligopeptides, compositions provided unambiguous assignments disulfides involved. cystine differs that classical defensins, indicates beta-defensins defensins must have differently folded chains, though they share several functional properties.