Neurochemical Research

, Volume 24, Issue 1, pp 37–42

Inactivation of the Purified Bovine μ Opioid Receptor by Sulfhydryl Reagents

  • Theresa L. Gioannini
  • Irma Onoprishvili
  • Jacob M. Hiller
  • Eric J. Simon
Article

DOI: 10.1023/A:1020923928936

Cite this article as:
Gioannini, T.L., Onoprishvili, I., Hiller, J.M. et al. Neurochem Res (1999) 24: 37. doi:10.1023/A:1020923928936

Abstract

We have investigated the role of cysteine residues in a highly purified μ opioid receptor protein (μORP) by examining the effect of -SH reagents on the binding of opioid ligands. Treatment of μORP, which is devoid of additional proteins, eliminates complications that arise from reaction of -SH reagents with other components, such as G proteins. Reagents tested include N-ethylmaleimide, 5,5′-dithiobis(2-nitrobenzoic) acid, and two derivatives of methanethiosulfonate. Specific opioid binding was inactivated by micromolar concentrations of all -SH reagents tested. Agonist binding ([3H]DAMGO) was much more sensitive to inactivation than antagonist binding ([3H]bremazocine). Prebinding μORP with 100 nM naloxone protected antagonist and agonist binding from inactivation by -SH reagents. The results of these experiments strongly suggest that at least one, and possibly more, reactive cysteine residue(s) is present on the μ opioid receptor protein molecule, positioned near the ligand binding site and accessible to -SH reagents.

Purified opioid receptor sulfhydryl reagent cysteine 

Copyright information

© Plenum Publishing Corporation 1999

Authors and Affiliations

  • Theresa L. Gioannini
    • 1
  • Irma Onoprishvili
    • 2
  • Jacob M. Hiller
    • 2
  • Eric J. Simon
    • 2
  1. 1.Natural Sciences Dept, Baruch CollegeCity University of New YorkNew York
  2. 2.Dept. of PsychiatryNew York University Medical CenterNew York

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