b-D-N-Acetylhexosaminidase (EC 3.2.1.52)^1,2

b-D-N-Acetylhexosaminidase, a highly purified enzyme (almost electrophoretically homogeneous) from jack bean meal, can cleave terminal b-D-N-acetylgalactosaminyl or b-D-N-acetylglucosaminyl linkages in glycoconjugates. It liberates terminal b-D-N-acetylhexosaminyl residues from various glyconconjugates such as ovalbumin glycopeptides, ovomucoid, N,N'-diacetylchitobiose, a,-acid glycoprotein which is free of sialic acid and galactose, globoside, asialo GM2, and various steroid b-D-N-acetylglucosaminides.

The optimum pH of this enzyme is between 5.0 amd 6.0 with p-nitrophenyl-b-D-N-acetylglucosaminide as substrate and between pH 3.5 and 4.0 with p-nitrophenyl-b-D-N-acetylgalactosaminide as substrate. Acetate ion is a moderate inhibitor for this enzyme; therefore, the use of acetate buffer above 20 mM concentration should be avoided. This enzyme is stable at 4°C.

The specific activity of this preparation is about 270 units per mg protein. This preparation is essentially devoid of all other exo-glycosidases, endo-glycosidases and proteases, except for a trace of a-D-galactosidase activity. The ratio of b-D-hexosaminidase to a-D-galactosidase is 1 to 4 x 10^-6. This enzyme is supplied in liquid form which contains 0.5 unit/µl. One unit of the enzyme is defined as the amount of enzyme that hydrolyzes 1 µmole of p-nitrophenyl-b-D- N-acetylglucosaminide per minute at 37°C.

References 1.Li, S.-C., and Li, Y.-T. (1970) J. Biol. Chem. 245, 5153-5160. 2.Li, Y.-T., and Li, S.-C. (1972) Methods Enzymol. 28, 702-713.

10 unit vial - Concentration: 0.26 units/µl in 25 mM phosphate buffer, pH 7.0