SEARCH

SEARCH BY CITATION

Abstract

  1. Top of page
  2. Abstract
  3. REFERENCES

Apoenzyme of aspartate aminotransferase prepared according to various techniques can bind the pyridoxamine-P coenzyme and recover its full activity. An anticooperativity is observed between the two sites of the dimer; the intrinsic dissociation constants are 20 nM and 200 nM for apoenzymes prepared in the presence of phosphate and less than 1.8 and 6 nM for an apoenzyme prepared without phosphate. The phosphate ions can bind to two sites of the apoenzyme with an intrinsic constant of 1.6 μM; a competition is observed between pyridoxamine-P and phosphate but it is not sufficient to explain the observed differences between the various apoenzymes. At pH 8.3, pyridoxamine-P can dissociate from the holoenzyme: the dissociation rate is very slow so that it does not occur in enzymatic transamination.

In the presence of succinate, the two sites become equivalent and the affinity for pyridoxamine-P is smaller, meaning the occurence of an interaction between the substrate-binding site and the coenzyme-binding site.

Enzyme
 

Aspartate aminotransferase or l-aspartate: 2-oxoglutarate aminotransferase (EC 2.6.1.1)

REFERENCES

  1. Top of page
  2. Abstract
  3. REFERENCES
  • 1
    Fasella, P. (1968) in Pyridoxal Catalysis: Enzymes and Model Systems (Snell, E. E., Braunstein, A. E., Severin, E. S. & TorchinskyYu. M., eds) pp. 130, Pergamon Press, New York .
  • 2
    Martinez-Carrion, M., Turano, C., Chiancone, E., Bossa, F., Giartosio, A., Riva, F. & Fasella, P. (1967) J. Biol. Chem. 242, 23972409.
  • 3
    Velick, S. F. & Vavra, J. (1962) J. Biol. Chem. 237, 21092112.
  • 4
    Christen, P. & Riordan, J. F. (1970) Biochemistry, 9, 30253034.
  • 5
    Cournil, I. & Arrio-Dupont, M., Biochimie in press.
  • 6
    Arrio-Dupont, M. (1969) Biochem. Biophys. Res. Commun. 36, 306311.
  • 7
    Jenkins, W. T., Yphantis, D. A. & Sizer, I. W. (1959) J. Biol. Chem. 234, 5157.
  • 8
    Arrio-Dupont, M., Cournil, I. & Duie, P. (1970) FEBS Lett. 11, 144146.
  • 9
    Karmen, A. (1955) J. Clin. Invest. 34, 131133.
  • 10
    Scardi, V., Scotto, P., Iaccarino, M. & Scarano, E. (1963) Biochem. J. 88, 171175.
  • 11
    Dixon, H. B. F. & Severin, E. S. (1968) Biochem. J. 110, 18 p.
  • 12
    Furbish, F. S., Fonda, M. L. & Metzler, D. (1969) Biochemistry, 8, 51695180.
  • 13
    Wada, H. & Snell, E. E. (1962) J. Biol. Chem. 237, 127132.
  • 14
    Grindey, G. B. & Nichol, C. A. (1970) Anal. Biochem. 33, 114119.
  • 15
    Churchih, J. E. & Farrelly, J. G. (1969) J. Biol. Chem. 244, 7276.
  • 16
    Arrio-Dupont, M. (1970) Photochem. Photobiol. 12, 297315.
  • 17
    Churchih, J. E. & Farrelly, J. G. (1969) J. Biol. Chem. 244, 36853690.
  • 18
    Martinez-Carrion, M., Kuczenski, R., Tiemeier, D. C. & Peterson, D. L. (1970) J. Biol. Chem. 245, 799805.
  • 19
    Scatchard, G. (1949) Ann. N. Y. Acad. Sci. 51, 660672.
  • 20
    Jenkins, W. T. & D'Ari, L. (1966) Biochem. Biophys. Res. Commun. 22, 376382.
  • 21
    Jenkins, W. T. & D'Ari, L. (1966) J. Biol. Chem. 241, 56675674.
  • 22
    Cheng, S., Michuda-Kozak, C. & Martinez-Carrion, M. (1971) J. Biol. Chem. 246, 36233630.
  • 23
    Farrelly, J. G. & Churchich, J. E. (1968) Biochim. Biophys. Acta, 167, 280290.
  • 24
    Polyanovsky, O. L. & Ivanov, V. I. (1964) Biokhimiya, 29, 728734.
  • 25
    Banks, B. E. C., Doonan, S., Gauldie, J., Lawrence, A. J. & Vernon, C. A. (1968) Eur. J. Biochem. 6, 507513.
  • 26
    Melander, W. R. (1970) Ph. D. Thesis, Cornell University.
  • 27
    Feliss, N. & Martinez-Carrion, M. (1970) Biochem. Biophys. Res. Commun. 40, 932940.
  • 28
    Polyanovsky, O. L. & Vorotnitskaya, N. E. (1965) Biokhimiya, 30, 619627.
  • 29
    Ovchinnikov, Yu. A., Kiryushkin, A. A., Egorov, Ts. A., Abdulaev, N. G., Kiselev, A. P., Modyanov, N. N., Grishin, E. V., Sukhikh, A. P., Vinogradova, E. I., Feigina, &I. Yu., Aldanova, N. A., Lipkin, V. M., Braunstein, A. E., Polyanovsky, O. L. & Nosikov, V. V. (1971) FEBS Lett. 133136.
  • 30
    Kopelovich, L., Sweetman, L. & Nisselbaum, J. S. (1970) J. Biol. Chem. 245, 20112017.
  • 31
    Marino, G., DeRosa, M., Buonocore, V. & Scardi, V. (1969) FEBS Lett. 5, 347350.
  • 32
    Koshland, D. E. Jr., Nemethy, G. & Filmer, D. (1966) Biochemistry, 5, 365385.
  • 33
    Levitski, A. & Koshland, D. E., Jr. (1969). Proc. Nat. Acad. Sci. U. S. A. 62, 11211128.
  • 34
    Monod, J., Wyman, J. & Changeux, J. P. (1965) J. Mol. Biol. 12, 88118.
  • 35
    Fasella, P. & Turano, C. (1970) Vitamins Hormones, 28, 157194.
  • 36
    Ivanov, V. I. & Karpeisky, M. Ya. (1969) Advan. Enzymol. 32, 2153.
  • 37
    Lazdunski, M., Petitclerc, C., Chappelet, D. & Lazdunski, C. (1971) Eur. J. Biochem. 20, 124139.