Bibliographic Citation
| Document | For copies of Journal Articles, please contact the Publisher or your local public or university library and refer to the information in the Resource Relation field. For copies of other documents, please see the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or Document Availability. |
|---|---|
| Title | Phosphoprotein phosphatase of bovine spleen cell nuclei: physicochemical properties |
| Creator/Author | Rezyapkin, V.I. ; Leonova, L.E. ; Komkova, A.I. |
| Publication Date | 1986 Jan 10 |
| OSTI Identifier | OSTI ID: 5933374 |
| Other Number(s) | Journal ID: CODEN: BIORA |
| Resource Type | Journal Article |
| Resource Relation | Journal Name: Biochemistry (Engl. Transl.); (United States); Journal Volume: 50:7; Other Information: Translation from Biokhimiya; 50: No. 7, 1067-1075(Jul 1985) |
| Research Org | A.A. Zhdanov Leningrad State Univ., USSR |
| Subject | 59 BASIC BIOLOGICAL SCIENCES; CELL NUCLEI; RADIOENZYMATIC ASSAY; PHOSPHATASES; CATALYTIC EFFECTS; ENZYME ACTIVITY; SPLEEN CELLS; ADP; AMMONIUM COMPOUNDS; ATP; BIOLOGICAL EFFECTS; CASEIN; CATTLE; ELECTROPHORESIS; ENZYMATIC HYDROLYSIS; ENZYME INHIBITORS; LABELLED COMPOUNDS; MOLYBDATES; PHOSPHORUS 32; PROTEINS; SODIUM FLUORIDES; SUBSTRATES; ALKALI METAL COMPOUNDS; ANIMAL CELLS; ANIMALS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CELL CONSTITUENTS; CHEMICAL REACTIONS; DAYS LIVING RADIOISOTOPES; DECOMPOSITION; DOMESTIC ANIMALS; ENZYMES; ESTERASES; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; HYDROLASES; HYDROLYSIS; ISOTOPES; LIGHT NUCLEI; LYSIS; MAMMALS; MOLYBDENUM COMPOUNDS; NUCLEI; NUCLEOTIDES; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANIC PHOSPHORUS COMPOUNDS; OXYGEN COMPOUNDS; PHOSPHORUS ISOTOPES; RADIOISOTOPES; REFRACTORY METAL COMPOUNDS; RUMINANTS; SODIUM COMPOUNDS; SOLVOLYSIS; SOMATIC CELLS; TRANSITION ELEMENT COMPOUNDS; VERTEBRATES |
| Description/Abstract | The physicochemical properties of phosphoprotein phosphatase (EC 1.3.1.16) from bovine spleen cell nuclei were studied. The enzyme possesses broad substrate specificity and catalyzes the dephosphorylation of phosphocasein, ATP, ADP, and p-nitrophenyl phosphate (pNPP). K/sub m/ for ATP, ADP, and pNPP are equal to 0.44, 0.43, and 1.25 mM, respectively. M/sub r/ of the enzyme, according to the data of gel filtraction of Sephadex G-75 and electrophoresis in polyacrylamide gel of various concentrations is approx. 33,000. In electrophoresis in the presence of SDS, two protein bands with M/sub r/ 12,000 and 18,000 are detected. In the enzyme molecule, acid amino acid residues predominate; two free SH groups and two disulfide bridges are detected. Phosphoprotein phosphatase is a glycoprotein, containing approx. 22% carbonhydrates. The protein possesses a supplementary absorption maximum at 560 nm. Ammonium molybdate is a competitive inhibitor with K/sub i/ 0.37 ..mu..M, while sodium fluoride is a noncompetitive inhibitor with K/sub i/ 1.3 mM. Incubation in the presence of 2 mM phenylmethylsulfonyl fluoride for 25 h leads to a loss of approx. 46% of the enzymatic activity. Ammonium molybdate, sodium fluoride, and PMSF are reversible inhibitors. Modifications of the SH groups, NH/sub 2/ groups, and histidine leads to a decrease in the enzymatic activity. Incubation of phosphoprotein phosphatase with (..gamma..-/sup 32/P)ATP leads to the incorporation of 0.33 mole /sup 33/P per mole of the enzyme. The mechanism of hydrolysis of the phosphodiester bond, catalyzed by the enzyme, is discussed. |
| Country of Publication | United States |
| Language | English |
| Format | Medium: X; Size: Pages: 902-910 |
| System Entry Date | 2008 Feb 07 |
Top | |
Last Updated: 11/19/2009