Isolation of pisumin, a novel antifungal protein from legumes of the sugar snap pea Pisum sativum var macrocarpon.

An antifungal protein with a novel N-terminal sequence GVGAAYGCFG and a molecular mass of 31 kDa was isolated from the legumes of the sugar snap pea Pisum sativum var. macrocarpon. The protein, designated pisumin, exhibited antifungal activity against Coprinus comatus and Pleurotus ostreatus and much weaker activity against Fusarium oxysporum and Rhizoctonia solani. Pisumin inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC(50) of 6 microM. Pisumin was similar to other leguminous antifungal proteins in that it was adsorbed on Affi-gel blue gel and CM-Sepharose.