Action of chondroitinases. I. The mode of action of two chondroitinase-AC preparations of different origin.

The modes of action of two chondroitinases-AC [EC 4.2.2.5] from Arthrobacter aurescens and Flavobacterium heparinum were examined. By comparison of the increase of viscosity and by analyses of digests using paper chromatography and gel filtration, it was shown that the Arthrobacter enzyme (A-Chase) degrades the substrate by a stepwise attack, while the Flavobacterium enzyme (F-Chase) exhibits a more random attack, though the first attack of both enzymes is of endo-type. Further study was carried out of the initial rate and final extent of the enzymic degradation of various mucopolysaccharides. The order of the initial rates at which the native mucopolysaccharides are degraded was similar for both enzymes. For A-Chase, the initial rate and final extent of degradation of modified chondroitin sulfate C or chondroitin methyl ester, however, were low compared with those of F-Chase. These results also suggested that A-Chase degrades the substrate by stepwise attack and F-Chase by random attack.