抄録
While the isolated soil bacterium, Arthrobacter aurescens, had been found to secrete a chondroitinase AC into the culture medium, it was recognized that the chondroitinase preparation obtained from the broth of the strain cultured in a jar fermentor contained at least three electrophoretically separable components of the enzyme. Each component (named chondroitinase I, II, and III, respectively) was separated from the others by use of isoelectric focusing and then the enzymic properties of each component were examined.
The value of isoelectric point of each component differed from one another (I, 5.5; II, 5.9; III, 6.4). However, no difference could be detected in pH-stability (pH 5.0 to 7.5), optimum pH (pH 6.0), thermal stability (below 45°C), optimum temperature (50°C), substrate specificity (chondroitin A and C lyase), mode of action (endo type, the degree of multiple attack was 3.0 to 3.1), and the dissociation constant of the enzyme-substrate complex (Km for chondroitin sulfate C was 3.3_??_3.6×10-4M). Thus the electrophoretically separable components with the chondroitinase activity were thought to be the multiple forms of the enzyme, chondroitinase AC. There was also no appreciable difference in the molecular weight values of those chondroitinase components, however, considerable difference was detected in the carbohydrate content of those components.
