Actinchinin, a novel antifungal protein from the gold kiwi fruit

Abstract

An antifungal protein designated actinchinin, with an N-terminal sequence different from that of the thaumatin-like antifungal protein from green kiwi fruit, was isolated from the gold kiwi fruit. The antifungal protein, unlike its counterpart from green kiwi fruit, did not exert antifungal activity against Botrytis cinerea, but was active against Fusarium oxysporum which was unresponsive to thaumatin-like protein from green kiwi fruit. Actinchinin was isolated using a protocol that comprised ion exchange chromatography on CM-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono S, and gel filtration by FPLC on Superdex 75. Actinchinin was adsorbed on CM-cellulose, Affi-gel blue gel and Mono S. It was devoid of mitogenic activity toward mouse splenocytes. In contrast to thaumatin-like protein from green kiwi fruit, actinchinin lacked HIV-1 reverse transcriptase inhibiting activity.