title: Purification of gonadotropin surge-inhibiting factor from Sertoli cell-enriched culture medium.
abstract: Gonadotropin surge-inhibiting factor (GnSIF) is a novel biological factor in follicular fluid that inhibits the pre-ovulatory LH and FSH surges. Recent studies suggest that the biological activity of GnSIF can be attributed to inhibin. Preliminary studies showed that the Sertoli cell-conditioned medium contains GnSIF-like biological activity. Using 32 liters of primary Sertoli cell-enriched culture medium and an in vitro pituitary bioassay, GnSIF was isolated. GnSIF is a single monomeric polypeptide (Mr of 37,000) with a partial N-terminal amino acid sequence of NH2-SDXXPQL which is distinct from any existing protein sequences. The identity of the inhibin that was separated from GnSIF was confirmed by direct protein sequencing. The purified GnSIF inhibited GnRH-stimulated LH- and basal FSH-release from pituitary cells cultured in vitro dose-dependently with a half maximal effective dose of about 1.4 ng/ml and 3.5 ng/ml, respectively. The half maximal effective dose of inhibin to suppress the pituitary GnRH-stimulated LH- and basal FSH-release was 2.5 ng/ml and 0.8 ng/ml, respectively. This study demonstrates that GnSIF is a unique protein that shares some biological activities with inhibin.
authors.affiliation: Population Council, Center for Biomedical Research, New York, New York 10021.
authors.forename: S
authors.initials: S
authors.lastname: Tio
authors.forename: D
authors.initials: D
authors.lastname: Koppenaal
authors.forename: C W
authors.initials: CW
authors.lastname: Bardin
authors.forename: C Y
authors.initials: CY
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D017077:Culture Media, Conditioned; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005640:Follicle Stimulating Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007265:Inhibins / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012708:Sertoli Cells / Q000166:cytology* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D017077:Culture Media, Conditioned; D011506:Proteins; D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone