Affordable Access

Sulfhydryl groups of aldosterone receptors from swine kidney.

Authors
Type
Published Article
Journal
Biochemical and biophysical research communications
Publication Date
Volume
124
Issue
1
Pages
51–56
Identifiers
PMID: 6238596
Source
Medline
License
Unknown

Abstract

Specific [3H]aldosterone binding activity in swine kidney cytosol was inactivated by pretreatment of the cytosol with monoiodoacetamide (pH 8.5), N-ethylmaleimide (pH 7.0), or 5,5'-dithiobis(2-nitrobenzoate) (pH 7.5). Dithiothreitol restored the specific binding activity inactivated by the nitrobenzoate, but not that inactivated with ethylmaleimide. Incubation of the cytosol with aldosterone prior to pretreatment with ethylmaleimide protected the receptors from inactivation. The rank order of steroids for the protection was: aldosterone greater than hydrocortisone greater than or equal to dexamethazone = progesterone greater than triamcinolone greater than estradiol. The initial velocity of the specific hormone binding could be determined by the binding reaction for 60 sec at 30 degrees. Double reciprocal plots of the initial velocity versus the hormone concentration with or without the nitrobenzoate showed a typical pattern of competition between the hormone and the inactivator. The results indicated the presence of functional sulfhydryl groups on the hormone binding sites of aldosterone receptors.

Statistics

Seen <100 times