BETA-HEXOSAMINIDASE ISOZYMES IN HUMAN COLONIC CARCINOMA

Abstract

Isoelectric focusing of crude extracts demonstrated that human colonic carcinomas contained a higher proportion of .beta.-hexosaminidase B than .beta.-hexosaminidase A, while normal human colonic mucosa contained a higher proportion of the A form of the enzyme. Studies of the isolated isozymes showed that .beta.-hexosaminidase B was more stable to heat and more active at low pH than .beta.-hexosaminidase A. Kinetic studies revealed that A and B forms of .beta.-hexosaminidase had essentially the same Km and Vmax for p-nitrophenyl-N-acetyl-.beta.-D-glucosaminide.