Advertisement

On the Mechanism of the Pentose Phosphate Epimerases

  • Linda Davis
    Affiliations
    From the Department of Biological Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110 and the Department of Biological Sciences, University of California, Santa Barbara, California 93106
    Search for articles by this author
  • Nancy Lee
    Affiliations
    From the Department of Biological Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110 and the Department of Biological Sciences, University of California, Santa Barbara, California 93106
    Search for articles by this author
  • Luis Glaser
    Affiliations
    From the Department of Biological Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110 and the Department of Biological Sciences, University of California, Santa Barbara, California 93106
    Search for articles by this author
      This paper is only available as a PDF. To read, Please Download here.
      The mechanism of the l-ribulose 5-phosphate 4-epimerase has been examined. In agreement with previous observations (Mcdonough, M. W., and Wood, M. A. (1961) J. Biol. Chem. 236, 1220) no exchange of hydrogen with H2O is observed. Suitable double label experiments indicate that hydrogen transfer in the reaction is intramolecular.
      The data for kinetics of the exchange of the hydrogen at C-3 of substrate catalyzed by a d-ribulose 5-phosphate 3-epimerase have been examined. The data indicate that the enzyme must contain two hydrogen donors (acceptors) which interact with the hydrogen at carbon 3 of d-ribulose 5-phosphate and d-xylulose 5-phosphate, respectively.

      REFERENCES

        • Glaser L.
        Boyer P.D. The Enzymes, Vol. VI. 3rd Ed. Academie Press, New York1972: 355-380
        • McDonough M.W.
        • Wood M.A.
        J. Biol. Chem. 1961; 236: 1220-1224
        • Lee N.
        • Patrick J.W.
        • Masson M.
        J. Biol. Chem. 1968; 243: 4700-4705
        • Melo A.
        • Elliott W.H.
        • Glaser L.
        J. Biol. Chem. 1968; 243: 1467-1474
        • Horecker B.L.
        Methods Enzymol. 1957; 3: 190-193
        • Horecker B.L.
        • Hurwitz J.
        • Stumpf P.K.
        Methods Enzymol. 1957; 3: 193-196
        • Bergmbyer H.U.
        Methods of Enzymatic Analysis. 1st Ed. Academic Press, New York1965
        • Brown A.H.
        Arch. Biochem. Biophys. 1946; 11: 269
        • Ames B.N.
        Methods Enzymol. 1966; 8: 115-118
        • Sawardeker J.S.
        • Sloneker J.H.
        • Jeanes A.
        Anal. Chem. 1965; 37: 1602-1604
        • Holmes W.F.
        • Holland W.H.
        • Parker J.A.
        Anal. Chem. 1971; 43: 1806-1811
        • Glaser L.
        • Ward L.
        Biochim. Biophys. Acta. 1970; 198: 613-615
        • Nelsestuen G.L.
        • Kirkwood S.
        J. Biol. Chem. 1971; 246: 7533-7543
        • Rose I.A.
        • O’Connell E.L.
        J. Biol. Chem. 1961; 236: 3086-3092
        • Rose I.A.
        Boyer P.D. The Enzymes, Vol. II. 3rd Ed. Academic Press, New York1970: 281-321
        • Williamson T.W.
        • Wood W.A.
        Methods Enzymol. 1966; 9: 605
        • Cardinale G.W.
        • Abeles R.H.
        Biochemistry. 1968; 5: 3971
        • Finlay T.H.
        • Adams E.
        J. Biol. Chem. 1970; 245: 5248-5260
        • Kenyon G.L.
        • Hegeman G.D.
        Biochemistry. 1970; 9: 4036
        • Jencks W.
        Catalysis in Chemistry and Enzymology. McGraw-Hill Book Co., New York1969: 209
        • Cram D.J.
        • Gösser L.
        J. Amer. Chem. Soc. 1964; 86: 2950
        • Dbupree J.D.
        • Wood W.A.
        J. Biol. Chem. 1972; 247: 3093-3097
        • Salo W.L.
        • Fossitt D.D.
        • Bevill R.D.
        • Kirkwood S.
        • Wood W.A.
        J. Biol. Chem. 1972; 247: 3098-3100