title: Fish gonadotropin(s). II. Isolation of gonadotropin(s) from chum salmon pituitary glands using affinity chromatography.
abstract: A highly purified gonadotropic hormone preparation has been obtained from chum salmon (Oncorhynchus keta) pituitaries by extraction with ethanolic or aqueous buffer, affinity chromatography on Con A Sepharose and gel filtration on Sephadex G-75 superfine. A purified fraction from Sephadex G-75 averaged 448 mug NIH-LH-S18/mg glycoprotein as measured by the uptake of radiophosphate into chick testes. A total of 1.1 g of salmon gonadotropin (s) (SG)/kg fresh tissue was recovered when the isolation began with an aqueous extraction. Analytical polyacrylamide gel electrophoresis (P.A.G.E.) of the purified fraction from Sephadex G-75 displayed a single broad zone in non-dissociating conditions and two bands in 8 M urea. Polyacrylamide gel electrofocusing yielded six sharp bands with an isoelectric point range of 4.38 to 5.05, and four bands with an isoelectric point range of 4.31 to 4.95 in 8 M urea. A molecular weight of 41,000 was determined by gel filtration. A subunit molecular weight of 17,800 +/- 10% was found by P.A.G.E. in 0.1% sodium dodecyl sulphate (SDS), suggesting that native SG consists of two subunits. Purified preparations were highly stable in Tris-Cl buffers and retained their activity for several months when stored at -73 degrees C.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002645:Chickens; D002846:Chromatography, Affinity; D000242:Cyclic AMP / Q000378:metabolism; D004355:Drug Stability; D005260:Female; D006065:Gonadotropins, Pituitary / Q000302:isolation & purification* / Q000494:pharmacology; D008297:Male; D008970:Molecular Weight; D010053:Ovary / Q000187:drug effects / Q000378:metabolism; D010902:Pituitary Gland / Q000032:analysis*; D012474:Salmon; D013737:Testis / Q000187:drug effects / Q000378:metabolism; D013972:Thyrotropin / Q000032:analysis; D014337:Trout
chemical_list: D006065:Gonadotropins, Pituitary; D013972:Thyrotropin; D000242:Cyclic AMP