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Properties of a Phosphoprotein Phosphatase from Bovine Heart with Activity on Glycogen Synthase, Phosphorylase, and Histone

Open AccessPublished:October 25, 1974DOI:https://doi.org/10.1016/S0021-9258(19)42179-0
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      A phosphoprotein phosphatase has been purified approximately 150-fold from bovine heart. This preparation catalyzed both the conversion of heart glycogen synthase D into I and skeletal muscle phosphorylase a into b, and also the dephosphorylation of synthase D, phosphorylase a, active phosphorylase kinase, phosphorylated histone, and phosphorylated casein. The ratios of the activities of the phosphatase on synthase, phosphorylase, and histone substrates remained constant throughout the purification of this enzyme. These results support our previous conclusion that the same enzyme may act on several phosphorylated substrates in heart.
      The Km values of the enzyme for dephosphorylation of synthase D, phosphorylase a, and histone were determined and each was increased by adding an alternative phosphoprotein substrate to the reaction mixture. Adenosine and uridine nucleotides were potent inhibitors of the phosphatase with either synthase D or phosphorylase a as substrate, but rather ineffective with histone as substrate. Mg2+, Ca2+, and Mn2+ were activators of the activity with synthase D or histone as substrate but inhibitors with phosphorylase a. Citrate and glycogen acted as specific inhibitors for synthase dephosphorylation, and albumin and gelatin were specific inhibitors with phosphorylase a. Some of the inhibitory effects on glycogen synthase dephosphorylation could be reversed by either glucose-6-P or Mg2+. The above results show the importance of the substrate in the regulation of the phosphoprotein phosphatase in heart tissue.

      REFERENCES

        • Nakai C.
        • Thomas J.A.
        Fed. Proc. 1973; 23: 604
        • Villar-Palasi C.
        • Larner J.
        Vitamins Hormones. 1969; 26: 65
        • Graves D.H.
        • Fischer E.H.
        • Krebs E.G.
        J. Biol. Chem. 1960; 235: 805
        • Villar-Palasi C.
        Ann. N. Y. Acad. Sci. 1969; 166: 719
        • Kato K.
        • Bishop J.S.
        J. Biol. Chem. 1972; 247: 7420
        • Nakai C.
        • Thomas J.A.
        Biochem. Biophys. Res. Commun. 1973; 52: 530
        • Zieve F.J.
        • Glinsmann W.H.
        Biochem. Biophys. Res. Commun. 1973; 50: 872
        • England P.J.
        • Stull J.T.
        • Krebs E.G.
        J. Biol. Chem. 1972; 247: 5275
        • Thomas J.A.
        • Schlender K.K.
        • Larner J.
        Anal. Biochem. 1968; 25: 486
        • Glynn I.M.
        • Chappell J.B.
        Biochem. J. 1964; 90: 147
        • Brown N.E.
        • Larner J.
        Biochim. Biophys. Acta. 1971; 242: 69
        • Thomas J.A.
        • Larner J.
        Biochim. Biophys. Acta. 1973; 293: 62
        • Fischer E.H.
        • Krebs E.G.
        Methods Enzymol. 1962; 5: 369
        • Brostrom C.O.
        • Hunkeler F.L.
        • Krebs E.G.
        J. Biol. Chem. 1971; 246: 1961
        • Hurd S.S.
        • Novoa W.B.
        • Hickenbottom J.P.
        • Fischer E.H.
        Methods Enzymol. 1966; 8: 546
        • Reimann E.M.
        • Walsh D.A.
        • Krebs E.G.
        J. Biol. Chem. 1971; 246: 1986
        • Rubin C.S.
        • Erlichman J.
        • Rosen O.M.
        J. Biol. Chem. 1972; 247: 36
        • Thomas J.A.
        • Nakai C.
        J. Biol. Chem. 1973; 248: 2208
        • Meisler M.H.
        • Langan T.A.
        J. Biol. Chem. 1969; 244: 4961
        • Thomas J.A.
        • Schlender K.K.
        • Larner J.
        Biochim. Biophys. Acta. 1973; 293: 84
        • Illingworth B.
        • Cori G.T.
        Biochem. Prep. 1953; 3: 1
        • Dubois M.
        • Gilles K.A.
        • Hamilton J.K.
        • Rebers P.A.
        • Smith F.
        Anal. Chem. 1956; 28: 350
        • Lowry O.H.
        • Rosebrough N.J.
        • Farr A.L.
        • Randall R.J.
        J. Biol. Chem. 1951; 193: 265
      1. Sigma Technical Bulletin No. 104. Sigma Chemical Co., St. Louis1971: 6
        • Maeno H.
        • Greengard P.
        J. Biol. Chem. 1972; 247: 3269
        • Martensen T.M.
        • Brotherton J.E.
        • Graves D.J.
        J. Biol. Chem. 1973; 248: 8329
        • Rosull-Perez M.
        • Villar-Palasi C.
        • Larner J.
        Biochemistry. 1962; 1: 763
        • Stalmans W.
        • DeWulf H.
        • Hers H-G.
        Eur. J. Biochem. 1971; 18: 582