Hypogin, a novel antifungal peptide from peanuts with sequence similarity to peanut allergen

A protein designated hypogin, with a prominent suppressive action on the growth of the fungi Mycosphaerella arachidicola, Fusarium oxysporum and Coprinus comatus, was isolated from seeds of the peanut Arachis hypogaea. The protein inhibited human immunodeficiency virus (HIV) reverse transcriptase and enzymes associated with HIV infection including alpha-glucosidase and beta-glucosidase. The proliferative response of mouse splenocytes was attenuated in the presence of the protein. The protein exhibited a molecular mass of 7.2 kDa in tricine gel electrophoresis and gel filtration on Superdex 75 and an N-terminal sequence resembling peanut allergen Ara H1. The isolation procedure involved affinity chromatography on Affi-gel blue gel and ion-exchange chromatography on CM-Sepharose. The protein was adsorbed in both chromatographic media.