A highly stable beta-glucosidase from the viscera of China white jade snail was purified to apparent homogeneity. This purified glucosidase consisted of two identical subunits with a native molecular mass of approximately 230 kDa. The maximal activity to p-nitrophenyl-beta-(D)-glucopyranoside (pNPG) occurred at 70 degrees C and pH 5.6. Its most notable characteristic was stable over a wide pH range (3-11 at 30 degrees C for 24 h) and a relatively high temperature (60 degrees C for 24 h). The K-m for pNPG was 0.338 mM and the V-max was 0.25 mmol nitrophenol/min/mg glucosidase at pH 5.6 and 50 degrees C. Compared to its activity against pNPG (100%), the beta-glucosidase exhibited low levels of activity against other aryl-glycosides (less than 1%). Additionally, the enzyme hydrolyzed the 20-C, beta-(1 -> 6)-glucoside of ginsenoside Rb-1 to produce ginsenoside Rd, but did not hydrolyze the other beta-(D)-glucosidic bonds of Rb-1. The properties of the enzyme could make it become a useful tool in biotransformation of glucosides. (c) 2006 Elsevier Ltd. All rights reserved.