title: Purification and partial characterization of two acid phosphatase forms from pearl oyster (Pinctada fucata).
abstract: The present study describes the details about the acid phosphatase forms in the pearl oyster, Pinctada fucata. Two isoenzymes (AcPase I and II) of acid phosphatase were separated and purified from viscera of pearl oyster, P. fucata to homogeneity by chromatography on DEAE-Sepharose Fast Flow, Sephadex G-200 superfine and ConA Sepharose 4B, and partial biochemical properties of AcPase I and II were studied. AcPase I and AcPase II had molecular weights of 208.8 and 64.3 kDa, respectively. AcPase I was a single polypeptide chain, while AcPase II was a dimeric enzyme composed of two equivalent subunits. AcPase I and II showed optimal pHs at 4.6 and 3.2 with p-nitrophenylphosphate as substrate. The optimal catalytic reaction temperature was 47 degrees C for AcPase I and 57 degrees C for AcPase II. Both enzyme forms were stable when incubated at 50 degrees C for 40 min. Tartrate and fluoride were the most effective inhibitors of the enzymes. Fe(3+), Zn(2+), Cu(2+) and Pb(2+) inhibited the activity of AcPase I and II to differing extents. AcPase I and II were apparently nonspecific and hydrolyzed various phosphoric esters. The different properties of AcPase I and II suggested that the two enzymes may play different roles in the pearl oyster.
authors.affiliation: Institute of Marine Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
authors.forename: Gu
authors.initials: G
authors.lastname: Jing
authors.forename: Lingyu
authors.initials: L
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.forename: Liping
authors.initials: L
authors.lastname: Xie
authors.forename: Rongqing
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000135:Acid Phosphatase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D004791:Enzyme Inhibitors; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes; D008970:Molecular Weight; D049911:Pinctada / Q000201:enzymology*; D021122:Protein Subunits
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D021122:Protein Subunits; D000135:Acid Phosphatase