The bactericidal activity of pediocin PA-1 is specifically inhibited by a 15-mer fragment that spans the bacteriocin from the center toward the C terminus

A 15-mer peptide fragment derived from pediocin PA-1 (from residue 20 to re sidue 34) specifically inhibited the bactericidal activity of pediocin PA-1 . The fragment did not inhibit the pediocin-like bacteriocins sakacin P, le ucocin A, and curvacin A to nearly the same extent as it inhibited pediocin PA-1. Enterocin A, however, was also significantly inhibited by this fragm ent, although not as greatly as pediocin PA-1. This is consistent with the fact that enterocin A contains the longest continuous sequence identical to that of pediocin PA-I in the region spanned by the fragment. The fragment inhibited pediocin PA-1 to a much greater extent than did the other 29 poss ible 15-mer fragments that span pediocin PA-1. The results suggest that the fragment-by interacting with the target cells and/or pediocin PA-1-interfe res specifically with pediocin-target cell interaction.