J. Ford, J. Nunley, Y. Li
Jul 1, 1973
Citations
0
Influential Citations
28
Citations
Journal
Analytical biochemistry
Abstract
Abstract A general method for a continuously monitored spectrophotometric assay of glycosidases at all values of pH using p -nitrophenyl glycosides is presented. The method is demonstrated specifically by the development of a routine assay for α-galactosidase from fig and Mortierella vinacea using p -nitrophenyl galactopyranoside (NPG) at pH 3.9 and 5.8, respectively, and also for jack bean meal β- N -acetylhexosaminidase using p -nitrophenyl-β-2-acetamido-2-deoxy- d -glucopyranoside (NPADG) at pH 5.0. A number of different wavelengths may be used for the assay depending upon the criterion of the user; maximum sensitivity at a selected pH, determination of enzyme pH optima with a pH-independent difference extinction coefficient, or the reduction of background absorbance for kinetic studies at high substrate concentrations.