Partial purification of a hypothalamic factor that inhibits gonadotropin-releasing hormone-stimulated luteinizing hormone release.
A protein that suppresses GnRH-stimulated LH release from dispersed rat anterior pituitary cells was purified from rat hypothalami by chromatography on Sephadex G-25, carboxymethyl cellulose, and high performance gel permeation. The final increase in inhibitory activity was 214-fold. The inhibitor is a glycoprotein with an apparent mol wt of 12,252 +/- 638, as determined by gel permeation on HPLC and electrophoreses as a monomer after treatment with 8 M urea. The inhibitor has a Stokes radius of 16 A, an S value of 2.14 +/- 0.08, an isoelectric point value near 4.1, and a frictional ratio of 1.05. A preliminary amino acid composition is presented.
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000502:physiology; D006727:Hormone Antagonists; D007028:Hypothalamic Hormones / Q000302:isolation & purification* / Q000502:physiology; D007031:Hypothalamus / Q000502:physiology*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D008970:Molecular Weight; D036361:Peptide Hormones; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D006727:Hormone Antagonists; D007028:Hypothalamic Hormones; D036361:Peptide Hormones; C051285:luteinizing hormone release-inhibiting factor, rat; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone