Photoaffinity labelling of mammalian beta-adrenergic receptors: metal-dependent proteolysis explains apparent heterogeneity.

Journal Article (Journal Article)

The beta-adrenergic receptors in membranes from rat and hamster lungs have been studies using the photoaffinity label p-azido-m-[125I]-iodobenzyl-carazolol. Previous work with several beta adrenergic photoaffinity probes has suggested heterogeneity of the labelled beta adrenergic receptor peptides with 2-3 receptor peptides generally being identified. We now report that rat and hamster lung membranes prepared either in the presence or absence of protease inhibitors reveal striking differences in the ratios of photoaffinity labelled peptides. In the rat lung the inclusion of protease inhibitors in the membrane preparation changes the ratios of the 64,000, 53,000 and 44,000 molecular weight peptides from 28:42:30 to 72:16:12. Similarly, in hamster lung membranes there is evidence of multiple photoaffinity labelled peptides in preparations without protease inhibitors while only one peptide (app. Mr = 64,000) is labelled in preparations with protease inhibitors. Of the inhibitors tested EDTA and EGTA were the most active in preventing appearance of multiple labelled peptides suggesting that metal-dependent proteolysis may be involved in the generation of apparent receptor peptide heterogeneity.

Full Text

Duke Authors

Cited Authors

  • Benovic, JL; Stiles, GL; Lefkowitz, RJ; Caron, MG

Published Date

  • January 27, 1983

Published In

Volume / Issue

  • 110 / 2

Start / End Page

  • 504 - 511

PubMed ID

  • 6301455

International Standard Serial Number (ISSN)

  • 0006-291X

Digital Object Identifier (DOI)

  • 10.1016/0006-291x(83)91178-6


  • eng

Conference Location

  • United States