Abstract:

Washed suspensions of group A, C, and G streptococci and group A L-forms possess phosphatase, esterase, and N-acetylglucosaminidase, respectively. Cell-free extracts, obtained from streptococci and Informs by mechanical disintegration or by treatment of group A streptococci with phage-associated lysin, possess, in addition to these enzymes, an adenosine triphosphatase (ATPase). Over 90% of the total ATPase and NAGAase and 50% of phosphatase and esterase activities were solubilized by cell breakage, indicating that the latter 2 enzymes are membrane-bound. A partial separation between the phosphatase, NAGAase, and ATPase was achieved by gel filtration of cell-free extracts on Sephadex G-200. Phosphatase was eluted with high molecular weight material excluded from the column. NAGAase and ATPase were associated with much lower molecular weight fractions, while esterase activity was present in both high and low molecular weight fractions. Studies on substrate specificity showed that fractions which split PNP-phosphate also split PNP-acetate and PNP-propionate fractions which split ATPase also split CTP, ITP, and GTP but to a lesser extent. Fractions which were active against β-napthylacetate also split β-naphthyl butyrate (15% efficiency); no activity against longer fatty acid esters of PNP or β-naphthyl derivatives was present.