Volume 36 (1988) Issue 8 Pages 3020-3026
Two forms, acid phosphatases A and B (APases A and B), of low-molecular-weight APases were highly purified. APases A and B showed isoelectric points ofapproximately 5.9 and 5.4, respectively, and the apparent molecular weights were estimated to be 15000 by Sephadex G-75 gel filtration or 14500 and 14000, respectively, by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis. Both enzymes catalyzed the hydrolysis of p-nitrophenyl phosphate, phosphotyrosine, and flavin mono-nucleotide, but APase A showed higher activity with lower Km value than APase B toward phosphotyrosine. APase B was effectively activated by purine compounds, whereas APase A was not. Some differences in sensitivity to inhibitors between APases A and B were also observed. These enzyme forms also existed in kidney, brain, and erythrocytes of the rat.