Chemical cross-linking of somatostatin receptors in rat adrenal cortex.
Adrenocortical somatostatin receptors have been shown to interact with somatostatin-14 (S-14) and somatostatin-28 (S-28). To determine whether these peptides interact with the same or different receptor proteins, we chemically cross-linked these receptors using disuccinimidyl suberate to radioligands prepared from tyrosinated S-14 and S-28 analogs. Sodium dodecylsulfate-polyacrylamide gel electrophoresis and subsequent autoradiography of [125I-Tyr11] S-14 and [Leu8, D-Trp22, 125I-Tyr25] S-28 cross-linked to their binding sites following solubilization in the presence of 50 mM DTT revealed the presence of a single labelled protein of Mr = 200,000. When the cross-linked material was treated under non-reducing conditions, this band was not observed. Furthermore, addition of excess S-14 and S-28 at the time of binding inhibited the incorporation of both radioligands into the receptor protein. These results demonstrate that adrenocortical membrane receptors for somatostatin contain a single receptor protein sub-unit or sub-units of identical size which interact with both S-14 and S-28.
D000302:Adrenal Cortex / Q000378:metabolism*; D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004229:Dithiothreitol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D046911:Macromolecular Substances; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D017481:Receptors, Somatostatin; D013004:Somatostatin / Q000378:metabolism; D053561:Somatostatin-28; D013388:Succinimides / Q000494:pharmacology
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D017981:Receptors, Neurotransmitter; D017481:Receptors, Somatostatin; D013388:Succinimides; D013004:Somatostatin; D053561:Somatostatin-28; D004229:Dithiothreitol; C019358:disuccinimidyl suberate