Purification and partial characterization of XXXX ovarian lutropin receptor.

@entity1 @entity3505 @entity3208 @entity19 @entity5 @entity7813 @entity2975 @entity35 @entity12142 @entity291
Lutropin (LH) receptor was solubilized from pseudopregnant @entity35 ovaries and purified by two cycles of affinity chromatography on @entity1 choriogonadotropin (hCG)-Affi-Gel 10. The purified receptor preparation contained a single class of high-affinity 125I-hCG binding sites with an equilibrium dissociation constant (Kd) of 5.1 X 10(-10) M (at 20 degrees C) and had a specific hormone binding capacity of 7920 pmol/mg of protein. The purified receptor migrated as a single 90-kDa band in @entity3208 - @entity2975 gel electrophoresis under both nonreducing and reducing conditions. Affinity cross-linking of the purified receptor to 125I-hCG produced a 130-kDa complex. Hormone-binding ability of the purified 90-kDa polypeptide was demonstrated also by ligand blotting. The purified receptor was electroblotted onto @entity12142 after @entity3208 - @entity2975 gel electrophoresis under nonreducing conditions followed by incubation with 125I-hCG. Autoradiography revealed labeling of a 90-kDa band. This labeling was displaced by unlabeled hCG and @entity1 LH but not by @entity1 follitropin or @entity35 prolactin. In addition, LH receptors of @entity291 corpora lutea and @entity19 @entity5 cells were shown by ligand blotting to contain a 90-kDa hormone binding unit, suggesting that @entity7813 structure is well conserved among @entity1 species. The purified @entity35 ovarian @entity7813 bound to immobilized @entity3505 germ agglutinin, implying that the receptor is a glycoprotein. These results demonstrate that the hormone-binding unit of @entity35 ovarian @entity7813 is a 90-kDa membrane glycopolypeptide.
