A second, slower inactivation process in acetylcholine receptor-rich membrane vesicles prepared from Electrophorus electricus

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Abstract

An agonist such as carbamylcholine or phenyltrimethylammonium induced a second, slower complete inactivation of acetylcholine receptor prepared from Electrophorus electricus. The rate of this inactivation of the receptor followed first-order kinetics. The rate constant of the inactivation increased with the agonist concentration until it reached a plateau, the value of which was 0.19 h−1 at 4.5 °C. The reaction was also temperature dependent, and the activation energy of the inactivation caused by 1 mm carbamylcholine was estimated to be 7.6 kcal/mol. The inactive receptor was reconverted to the active form with a rate constant of about 0.015 h−1 at 4.5 °C when the carbamylcholine concentration (0.1 mm) was reduced by 15-fold dilution in eel Ringer's solution. These results can be interpreted by adding, to the minimal reaction scheme proposed by the Hess group, a second, slower, reversible inactivation process either through the intact form or through the first desensitized form of the receptor binding two agonist molecules.

References (33)

  • F.J. Barrantes

    J. Mol. Biol

    (1978)
  • S.M. Sine et al.

    J. Biol. Chem

    (1981)
  • D.J. Cash et al.

    Anal. Biochem

    (1981)
  • G.O. Ramseyer et al.

    Anal. Biochem

    (1981)
  • H. Sugiyama et al.

    J. Mol. Biol

    (1976)
  • T. Claudio et al.

    Arch. Biochem. Biophys

    (1977)
  • T. Heidmann et al.

    Annu. Rev. Biochem

    (1978)
  • A. Karlin
  • B. Katz et al.

    J. Physiol

    (1957)
  • R.F. Bonner et al.

    Nature (London)

    (1976)
  • H.H. Grunhagen et al.

    J. Mol. Biol

    (1978)
  • S.M. Dunn et al.

    Biochemistry

    (1980)
  • R. Jurss et al.
  • U. Quast et al.

    Biochemistry

    (1978)
  • M. Kasai et al.

    J. Memb. Biol

    (1971)
  • G.P. Hess et al.

    Nature (London)

    (1979)
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