Identity of streptolysin-O and NAD-glycohydrolase (EC 3.2.2.5).

The homogeneity of purified NAD-glycohydrolase (EC 3.2.2.5) from Group C streptococci was demonstrated by analytical ultracentrifugation, disc electrophoresis and immunochemical analysis. Together with earlier characterization procedures the data show that the enzyme is homogenous in molecular seize, molecular form and electrophoretic charge. In addition, the enzyme has been shown to possess strong hemolytic activity which could be activated by thiol compounds. It was concluded from the analytical data that NAD-glycohydrolase- and Streptolysin-O-activities are catalytic functions of one protein molecule. Therefore the lysis of red blood cells by Streptolysin-O may be regarded as an enzymatic process catalyzed by an NAD-glycohydrolase.