Role of sulfhydryl groups in Y2 neuropeptide Y receptor binding activity

W. Li, R. G. MacDonald, T. D. Hexum

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Benextramine, a tetramine disulfide, irreversibly inhibits neuropeptide Y (NPY) binding to the 50-kDa Y2 NPY receptor in bovine hippocampus (Li, W., MacDonald, R. G., and Hexum, T. D. (1991) Eur. J. Pharmacol. 207, 89-91). Evidence is presented that this inhibition occurs through a thiol-disulfide exchange. Treatment of bovine hippocampal membranes with benextramine inhibited NPY affinity cross-linking to the 50-kDa receptor. This inhibition of labeling was not affected by washing the membranes, but could be completely reversed by the addition of several thiol reducing reagents, including reduced glutathione, β-mercaptoethanol, and cysteine. Benextramine inhibited 70% of NPY-specific labeling and was much more effective than other sulfhydryl reactive agents, such as oxidized glutathione, cystamine, and 5,5'-dithio-bis(2-nitro-benzoic acid). Furthermore, the sulfhydryl-modifying agents N-ethylmaleimide and p-chloromercuriphenyl-sulfonic acid specifically decreased NPY affinity labeling. Finally, NPY labeling of the 50-kDa receptor was reduced by the heavy metal ions Zn2+, Cu2+, and Hg2+. Preincubation with NPY prevented Y2 receptors from being inactivated by either 400 μM N- ethylmaleimide or 1 mM benextramine. These results suggest that one or more benextramine-sensitive sulfhydryl groups on the Y2 receptor are important for NPY binding activity.

Original languageEnglish (US)
Pages (from-to)7570-7575
Number of pages6
JournalJournal of Biological Chemistry
Volume267
Issue number11
StatePublished - 1992

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Role of sulfhydryl groups in Y<sub>2</sub> neuropeptide Y receptor binding activity'. Together they form a unique fingerprint.

Cite this