ENHANCEMENT OF ANTIMICROBIAL ACTIVITY OF NEUROPEPTIDE-Y BY N-TERMINALTRUNCATION

The activity of neuropeptide Y (NPY) against Candida albicans, which w as revealed to be fungicidal, was enhanced significantly by the trunca tion of amino acid residues at the N terminus. The most active peptide s (MICs, approximately 1 mu M) were about 10-fold more potent than the intact NPY (MIC, approximately 10 mu M). The enhancement was weakened by the replacement of the N terminus by negatively charged residues a nd/or acylation of the a-amino group. These results suggest that only the alpha-helical region of NPY is necessary for the antimicrobial act ivity and that the net charge of the peptide is important for the acti vity.