Studies on the enzymes of Sarcocystis suicanis: purification and characterization of an acid phosphatase.

Percoll density gradient centrifugation was used for isolating large quantities of bradyzoites of Sarcocystis suicanis, which were used for enzymatic analysis. Crude extracts of bradyzoites contained activities suggestive of several acid hydrolases. Levels of acid and alkaline phosphatase were higher than those of beta-N-acetylhexosaminidase and beta-galactosidase. Acid phosphatase was purified 156-fold with an overall recovery of 54% using DEAE-Sepharose 4B and Sephadex G-200 chromatography. The partially purified enzyme was not a glycoprotein and had a molecular weight of approximately 170,000. The enzyme was markedly inhibited by Cu++, Hg++, and iodoacetamide, suggesting the presence of a sulfhydryl group. Sodium tartrate caused strong inhibition of the enzyme. The acid phosphatase of S. suicanis appears to be a unique enzyme that cannot be classified under high or low molecular weight acid phosphatases of widely diverse origin.