A phosphoprotein phosphatase from ox brain

Rose, Sally; Heald, P. J.

doi:10.1042/bj0810339

Cited by 43 publications

(17 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The results reported here clearly indicate that the membrane-associated phosphoprotein phosphatases are sulfhydryl dependent but do not require divalent metal ions for maximal activity. The requirement for reduced -SH groups is in accord with the observations of Sundararajan and Sarma [45] and Paigen [46] but not with Rose and Heald [47]. The present system also differs from cytosol phosphoprotein phosphatases of rat brain [15] and mouse mitochondria1 enzyme [46] in its inability to be stimulated by divalent metal ions.…”

Section: Discussionsupporting

confidence: 76%

Solubilization and Characterization of Phosphoprotein Phosphatase(s) from Bovine Corpus‐Luteum Plasma Membranes

Azhar

Menon

1975

European Journal of Biochemistry

View full text Add to dashboard Cite

Plasma membrane fractions I and I1 isolated from bovine corpus luteum contain phosphoprotein phosphatases. Enzyme activities associated with both membrane fractions showed pH optima in the neutral range and were most active with phosphoprotamine as the exogenous substrate. The enzyme activity was partially inhibited by Co", Zn2+ and Fe2+. Dithioerythritol, glutathione (reduced) and 2-mercaptoethanol stimulated the enzyme activity, whereas N-ethylmaleimide and N-phenylmaleimide were inhibitory. Similarly, various cyclic nucleotides and nucleoside triphosphates also inhibited phosphoprotein phosphatase activities. The phosphatase activity was also observed with endogenous phosphorylated membrane proteins as substrate. The endogenous phosphorylation of membranes was rapid and attained a maximal level after 15-20 min of incubation. Initially endogenous dephosphorylation was also very rapid, but did not reach completion. In addition to phosphoprotein phosphatase, membrane preparations also possessed very active cyclic-AMP-dependent protein kinase activity. Phosphoprotein phosphatase activity from plasma membranes was solubilized by ionic and nonionic detergents. Optimal solubilization was achieved with 0

show abstract

Section: Discussionsupporting

confidence: 76%

Solubilization and Characterization of Phosphoprotein Phosphatase(s) from Bovine Corpus‐Luteum Plasma Membranes

Azhar

Menon

1975

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…The intrinsic phosphatase activity differs in several ways from the soluble casein phosphatase of brain studied by Rose & Heald (1961). The latter has a pH optimum of 5.9, is not significantly inhibited by Cu2+ or molybdate ions and is much less sensitive to zinc salts than is the intrinsic system.…”

Section: Resultsmentioning

confidence: 89%

“…Phosvitin was obtained from Nutritional Biochemicals Corp., Cleveland, Ohio, U.S.A., and purified by the procedure of Rose & Heald (1961). All chemicals were of the purest quality available.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…It is notable that in several tissues the intrinsic, but not the extrinsic, reaction is stimulated by low concentrations of cyclic AMP (Weller & Rodnight, 1970;Rodnight & Weller, 1971). In previous work from this laboratory on the intrinsic system turnover was not observed and it was uncertain to what extent the observed transfer of phosphorus to the membrane consisted of a phosphorylation of vacant serine hydroxyl groups or of an exchange of labelled phosphorus with phosphorylserine P. Further, membrane-bound phosphatases dephosphorylating intrinsic membrane proteins have not been described and the protein phosphatase in brain which dephosphorylates casein (Rose & Heald, 1961) is mainly located in the mitochondria and cell cytoplasm (Rose, 1962). The present work demonstrates a turnover of protein-bound phosphorylserine in membrane fragments and supports the conclusion that the transfer of phosphorus to the membrane involves the phosphorylation of serine hydroxyl groups.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Turnover of protein-bound phosphorylserine in membrane preparations from ox brain catalysed by intrinsic kinase and phosphatase activity

Weller¹,

Rodnight²

1971

Biochemical Journal

View full text Add to dashboard Cite

1. The turnover of protein-bound phosphorylserine in preparations of membrane fragments from ox brain cortex was studied. 2. Turnover was considered to arise from the action of intrinsic protein kinases and phosphatases on a membrane protein or proteins. 3. Properties of the kinase system were studied by measuring the rate of incorporation of 32p from y-labelled ATP into protein-bound phosphorylserine isolated from partial acid hydrolysates of membrane proteins. 4. Properties of the phosphatase system were studied by observing the rate of loss Of 32p from membrane preparations pre-labelled with [32P]ATP. 5. Net phosphorylation and clephosphorylation of membrane protein was observed during incubation of membrane preparations with and without ATP. 6. The rate of turnover was about 4ninol of P/h per mg of protein at 20°C; dephosphlorylation was considered to be the ratelinit,ing step.

show abstract

“…Allen ist gemeinsam, daß sie von zahl· reichen angebotenen Substraten wie Dipeptiden, Modellpeptiden, löslichen Hirnproteinen und physiologisch wichtigen Phosphatverbindungen nur selten eines in geringem Ausmaß angriffen, aber regelmäßig Phosphoproteide, meistens geprüft an Casein, aufgespalten haben (6,20 …”

Section: Introductionunclassified

Über Kathepsin, Phosphoproteid-Phosphatase und Saure Phosphatase in der löslichen Fraktion aus Rinderhirn-Cortex; Reinigung und Eigenschaften

Albert¹

1976

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Cathepsin, phosphoprotein-phosphatase and acid phosphatase in the soluble fraction of the cattle brain cortex: purification and propertiesSummary: Cattle brain cortex was homogenised in 0,29 mol/1 sucrose and centrifuged at 101 000 X g. The supernatant contains the majority of 3 enzymes participating in protein turnover: cathepsin (EC 3.4.4.23), phosphoprotein phosphatase (EC 3.1.3.16) and acid phosphatase (EC 3.1.3.2). They were separated by chromatography on Sephadex G 200 iii neutral buffer. The cathepsin was purified up to 380 fold by gel filtration on Sephadex and column electrophoresis. The pH optimum of cathepsin was 5.7. At 37°C no decrease of activity was measurable during 30 min. The K m was found to be 2.75 mg/ml Casein Härrimarsten. The molecular weight by gel filtration and exclusion-gel electrophoresis was about 45 000, corresponding to the cathepsin from human liver (Barrett, A. J. (1970) Biochem,. J. 117, 601-607). The sedimentation constant 3.9 S2Q, W * s comparable with the values of proteinase of different origin, and the composition is similar with respect to the high proportion of acidic amino acids. The phosphoprotein phosphatase can be further purified by chromatography on hydroxyapatite and by column electrophoresis. The pH optimum of phosphoprotein phosphatase was about pH 5.5. At 45 0 C no decrease of activity was measurable during 20 minj the K m was 1.43 jhg/ml casein isoelectric. The pH optimum of acid phosphatase was about 5.6. At 54 °C no decrease of activity was measurable during 30 min; the K m was 2 pmol/l for Sodium phenolphthalein diphosphate. All three enzymes slowly lost their activity during several weeks at -4°C, apparently by self digestion in the cold. *) Gefördert durch Mittel der Deutschen Forschungsgemeinschaft.

show abstract

A phosphoprotein phosphatase from ox brain

Cited by 43 publications

References 23 publications

Solubilization and Characterization of Phosphoprotein Phosphatase(s) from Bovine Corpus‐Luteum Plasma Membranes

Solubilization and Characterization of Phosphoprotein Phosphatase(s) from Bovine Corpus‐Luteum Plasma Membranes

Turnover of protein-bound phosphorylserine in membrane preparations from ox brain catalysed by intrinsic kinase and phosphatase activity

Über Kathepsin, Phosphoproteid-Phosphatase und Saure Phosphatase in der löslichen Fraktion aus Rinderhirn-Cortex; Reinigung und Eigenschaften

Contact Info

Product

Resources

About