EVIDENCE FOR A SINGLE ACTIVE-SITE IN BETA-D-GLUCOSIDASE BETA-D-FUCOSIDASE FROM DALBERGIA-COCHINCHINENSIS SEEDS/

Kinetic analyses have been done on the hydrolysis of p-nitrophenyl bet a-D-glucoside (PNPG) and p-nitrophenal beta-D-fucoside (PNPF) by the b eta-D-glucosidase/beta-D-fucosidase enzyme from Thai Rosewood (Dalberg ia cochinchinensis Pierre). PNPF showed a competitive inhibition of PN PG hydrolysis with a K-i of 0.42 mM. Hydrolysis of mixtures of PNPG an d PNPF at fractional ratios ranging from 0 to 1 showed Lineweaver-Burk plots intermediate between the two extremes, The apparent K-m and app arent V-max at each fractional ratio showed good correspondence with t he theoretical curves predicted for the existence of a single common a ctive site for the hydrolysis of the two substrates.