Isolation of luteinising hormone receptor binding inhibitor from bovine corpus luteum.
A luteinising hormone receptor binding inhibitor (LHRBI) has been purified from bovine corpus luteum (CL). Steroid-free extract of the CL was subjected to successive chromatographies on Sephadex G-50, Q-Sepharose, Orange A dye and metal chelate affinity columns followed by high performance-reverse phase and gel filtration columns. Purification was monitored by the ability of the fractions to inhibit the binding of 125I-human chorionic gonadotropin (hCG) to porcine granulosa cells in vitro. The final isolate showed an 8000-fold enrichment of activity. It was also capable of inhibiting porcine granulosa cell secretion of estradiol and progesterone (P) in vitro. Administration of LHRBI into follicle-stimulating hormone (FSH)-stimulated, immature rats strongly inhibited the ovarian ovulatory response to hCG as revealed by decreased P levels and the number of ova released. The M(r) of LHRBI as assessed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis was ca. 15 kDa and the pI was between 5.0 and 5.5.
Chari
S
S
Department of Gynecology, Endocrinology and Reproduction, Universitäts Frauenklinik, Marburg, Germany.
Kail
W
W
Daume
E
E
Sturm
G
G
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000378:metabolism; D003338:Corpus Luteum / Q000737:chemistry*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins; D010060:Ovulation / Q000187:drug effects; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology / Q000502:physiology; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D011974:Receptors, LH / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism; D013552:Swine
D006063:Chorionic Gonadotropin; D036341:Intercellular Signaling Peptides and Proteins; C011898:LH receptor binding inhibitor; D010455:Peptides; D011974:Receptors, LH; D011374:Progesterone; D004958:Estradiol