Alkaline phosphatase from human uterine myoma. I. Purification and some properties

Alkaline phosphatase from human uterine myoma was purified to homogeneity by butanol extraction, acetone precipitation, column chromatography on DEAE-cellulose, QAE-Sephadex and Con-A-Sepharose, gel filtration on Sephadex G-200 and preparative electrophoresis. The relative molecular mass (145 000), subunit mass (35 000), neutral sugars (7 micrograms/mg) and sialic acid (1 microgram/mg) content were estimated. pH optimum of the enzyme activity was 10.0-10.4, and Km for p-nitrophenyl phosphate was 0.23 mM. The enzyme was inhibited by Zn2+, phosphate, fluoride, EDTA and by treatment with neuraminidase. Mg2+ activated alkaline phosphatase and showed protective effect towards inhibition by EDTA and Zn2+. The uterine muscle alkaline phosphatase was also purified. It showed lower specific activity than myoma phosphatase, higher molecular mass (160 000) and subunit mass (76 400), higher neutral sugar and sialic acid content.