Characterization of a rutin-hydrolyzing enzyme with ?-glucosidase activity from tartary buckwheat (Fagopyrum tartaricum) seeds

The rutin-hydrolyzing enzyme (RHEs) catalyse hydrolysis of rutin to quercetin. In this study, a RHE purified from natural tartary buckwheat flour (FtRHE) exhibited ?-glucosidase activity. It was highly active on cello-oligosaccharides and p-nitrophenyl-?-D-glucopyranoside (pNPG). FtRHE optimum activity at 40 °C pH 4.0, which elevated by the presence Ca2+, suggesting that Ca2+ may act as co-factor for its activation. Km Vmax were 0.22 mM 310.48 U/mg, respectively, when pNPG substrate. retained only 6.6% in 1.5 M glucose, indicating glucose acted inhibitor. This study demonstrates provides better understanding role glycoside metabolism, establishing basis further investigations.