Midgut glands of abalone Haliotis discus contained two acid phosphatases [orthophosphoricmonoester phosphohydrolase (acid optimum), EC 18.104.22.168] separable by phosphocellulose column chromatography. They were designated as acid phosphatases I and II in order of elution and were purified 99- and 290-fold, respectively. Purified acid phosphatase II was. nearly homogeneous as judged by polyacrylamide gel electrophoresis. The substrate specificity of acid phosphatase I was narrow, whereas that of acid phosphatase II was broad. Good substrates for acid phosphatase I included p-nitrophenyl phosphate, phosphoenolpyruvate, inorganic pyrophosphate, and nucleoside di- and triphosphates. The acid phosphatases did not require any metal ion for maximum activity and were inhibited by Zn2+, Cu2+, and Hg2+. Fluoride and arsenate were potent inhibitors of both enzymes. The pH optima of acid phosphatases I and II were 5.9 and 5.5, respectively. The molecular weights of acid phosphatases I and II were estimated to be 28,000 and 100,000, respectively, by gel filtration on Sephadex G-l00. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that acid phosphatase II consists of two identical subunits.
|Number of pages||8|
|Journal||Journal of biochemistry|
|Publication status||Published - 1977 May|
ASJC Scopus subject areas
- Molecular Biology