An isolation procedure comprising affinity chromatography on Affi-gel blue
gel, ion exchange chromatography on SP-Toyopearl, and fast protein liquid c
hromatography on Mono S was used to purify a peptide from broad beans which
manifested antifungal activity toward Mycosphaerella arachidicola, Fusariu
m oxysporum, and Botrytis cinerea. The peptide demonstrated a molecular mas
s of 7.5 kDa. N-terminal sequence analysis disclosed the identity of the an
tifungal peptide to be a trypsin-chymotrypsin inhibitor. The trypsin-chymot
rypsin inhibitor also exerted an inhibitory action on chymotrypsin activity
and HIV-1 reverse transcriptase activity. Proliferation of murine splenocy
tes was stimulated in the presence of the trypsin-chymotrypsin inhibitor. T
his report constitutes the first observation of antifungal activity of a le
guminous peptidic protease inhibitor. (C) 2001 Academic Press.