Pomegranin, an antifungal peptide from pomegranate peels.

A new antifungal peptide designated as pomegranin, with an N-terminal sequence resembling that of rice disease resistance NB-S-LRR-like protein, was isolated from fresh pomegranate peels by ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and gel filtration by fast protein liquid chromatography on Superdex 75. Pomegranin was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel. It exhibited a molecular mass of 11 kDa in both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It inhibited mycelial growth in the fungi Botrytis cinerea and Fusarium oxysporum with an IC(50) of 2 microM and 6.1 microM, respectively. It was devoid of hemagglutinating, ribonuclease, deoxyribonuclease and protease inhibitory activities.