Purification And Characterization Of Human Prostatic Acid Phosphatase

Human prostatic acid phosphatase (orthophosphoric monoester phospho-hydrase, EC 3.1.3.2) is purified to homogeneity by standard procedures which include CM-Sephadex, Con A affinity chromatography and gel filtration. The purified enzyme is antigenically specific and has a M.W. of 100,000 with subunit M.W. of 48,000. However, the enzyme exhibited charge heterogeneity. Two major electrophoretic or chromatographic isozymic forms of PAP were separated by DEAE-Sephadex chromatography and their immunochemical identity was studied by immunodiffusion before and after the neuraminidase digestion. Quantitative precipitin and inhibition experiments showed immunological identity of the two chromatographic iso-zymes. Immunologic specificity of this enzyme resides on the protein moiety rather than the carbohydrate residue, although the latter group is mostly responsible for the charge group heterogeneity of the enzyme.