Proteinase activity in chondroitin lyase (chondroitinase) and endo-β-d-galactosidase (keratanase) preparations and a method to abolish their proteolytic effect on proteoglycan

Abstract

Significant amounts of proteinase activity have been found in chondroitin ABC lyase (EC 4.2.2.4), chondroitin AC II lyase and endo-beta-D-galactosidase (keratanase) from commercial sources. It would appear, therefore, that certain earlier biochemical and histochemical studies, which employed these commercial enzyme preparations for their presumed ability to degrade only glycosaminoglycans, may require re-evaluation. A mixture of EDTA, N-ethylmaleimide, phenylmethanesulphonyl fluoride and pepstatin abolishes the effect of the contaminating proteinases on proteoglycan with less significant effect on the chondroitin lyase or keratanase activity.