The porcine ovarian luteinizing hormone/human chorionic gonadotropin receptor II. Is the purified receptor an oligomer of identical subunits?
Purified porcine luteinizing hormone/human chorionic gonadotropin receptors were analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis following reduction and thermal denaturation and stained with Coomassie Brilliant Blue. A major protein of Mr = 77 +/- 4 X 10(3) and a minor protein of Mr = 66 +/- 4 X 10(3) were observed. Iodoreceptor proteins were resolved into a major component of Mr = 77 +/- 3 X 10(3) and a minor component of Mr = 62 +/- 5 X 10(3) after reduction and thermal denaturation. In the absence of reduction, the iodoreceptor had a major component of Mr 63 +/- 3 X 10(3). Purified human chorionic gonadotropin specifically transferred part of the iodoreceptor from the Mr = 63 X 10(3) species to an Mr = 110-120 X 10(3) species. Purified receptors were analyzed by nondenaturing polyacrylamide gel electrophoresis and identified by specific binding of iodo-human chorionic gonadotropin. Three binding species with approximate Mr = 60 X 10(3), 130 X 10(3), and 260 X 10(3) were identified. Iodoreceptors co-migrated with the Mr = 60 X 10(3) species under the same conditions. Similar results were obtained following renaturation of receptors separated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis without reduction and thermal denaturation. These results suggest for the first time that the porcine corpus luteum luteinizing hormone/human chorionic gonadotropin receptor may be a hormone binding monomer of Mr = 60-65 X 10(3), and that the monomer may associate to form hormone binding polymeric receptor complexes.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D006801:Humans; D007457:Iodine Radioisotopes; D046911:Macromolecular Substances; D008970:Molecular Weight; D011489:Protein Denaturation; D011956:Receptors, Cell Surface / Q000378:metabolism; D011974:Receptors, LH; D013552:Swine
D006063:Chorionic Gonadotropin; D007457:Iodine Radioisotopes; D046911:Macromolecular Substances; D011956:Receptors, Cell Surface; D011974:Receptors, LH