Beta adrenergic stimulation of protein carboxymethylation and amylase secretion in rat parotid gland.

Published

Journal Article

Protein carboxymethylase (S-adenosyl-l-methionine:protein-O-methyltransferase, EC 2.1.1.24) transfers methyl groups from S-adenosylmethionine to protein carboxyl groups. This cytosolic enzyme is found in highest concentration in secretory tissue and methylates membrane proteins. Stimulation of the parotid gland by catecholamines rapidly and reversibly increases protein carboxymethylase activity and methyl acceptor capacity of proteins in parotid homogenates. Isoproterenol was effective at concentrations causing amylase release in vivo and in vitro. Both enzyme activity and methyl acceptor capacity of proteins increased within 5 min, continued to increase for 30 min and then declined to control values within 60 min. The response to isoproterenol was stereospecific. The action of isoproterenol could be blocked by the beta adrenergic antagonist propranolol, while the alpha adrenergic agonist phenylephrine did not stimulate the enzyme or increase methyl acceptor proteins. Methyl acceptor proteins have been partially characterized by polyacrylamide gel electrophoresis. Although many proteins in the parotid are methylated, only two groups of methylated proteins increase after stimulation by isoproterenol.

Full Text

Duke Authors

Cited Authors

  • Strittmatter, WJ; Gagnon, C; Axelrod, J

Published Date

  • November 1, 1978

Published In

Volume / Issue

  • 207 / 2

Start / End Page

  • 419 - 424

PubMed ID

  • 712630

Pubmed Central ID

  • 712630

International Standard Serial Number (ISSN)

  • 0022-3565

Language

  • eng

Conference Location

  • United States