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A leguminous trypsin-chymotrypsin inhibitor Limenin with antifungal activity from Phaseolus limensis

Wang, Shaoyun, Rao, Pingfan
European food research & technology 2010 v.231 no.2 pp. 331-338
Alternaria alternata, Botrytis cinerea, Phaseolus, Pythium aphanidermatum, Salmonella, Staphylococcus aureus, amino acid sequences, ammonium sulfate, antifungal properties, hepatocytes, high performance liquid chromatography, ion exchange chromatography, isoelectric focusing, isoelectric point, lima beans, molecular weight, proteinase inhibitors
A trypsin-chymotrypsin inhibitor, designated Limenin, with both antifungal and antibacterial activity, and exhibiting a molecular mass of 18.0 kDa in SDS-polyacrylamide gel electrophoresis, was isolated from the large lima bean (Phaseolus limensis) legumes by a combination of extraction, ammonium sulfate precipitation, ion exchange chromatography on SP-Toyopearl and high performance liquid chromatography (HPLC) on Mono S. The isoelectric point was estimated to be 7.6 by isoelectric focusing. The 15 N-terminal amino acid sequences were determined to be DFVIDNEGNPLENGG, demonstrating some resemblance to those other protease inhibitors and inhibitor precursors from leguminous plants. It exerted potent antifungal action toward Botrytis cinerea, Alternaria alternata(Fr.) Keissl, and Pythium aphanidermatum. It showed antiproliferative activity toward tumor cells including human liver hepatoma cells Bel-7402 and neuroblastoma cells SHSY5Y. However, it had no effect on bacteria Staphylococcus aureus and Salmonella.