Purification and partial characterization of inhibin from porcine follicular fluid.
Inhibin, a protein of gonadal origin that suppresses the basal secretion of follicle stimulating hormone by anterior pituitary cells has been purified from porcine follicular fluid. Using several RP-HPLC steps and gel filtration under denaturing conditions, we obtained a fraction approximately ten thousand fold purified which showed one band on SDS PAGE and in the same experiment two bands after reduction (MW ca 14K and ca 18K) suggesting a molecular weight of 32K for inhibin. Edman degradation of isolated inhibin and carboxymethylated chain A indicated that the first 6 residues were H-Ser-Thr-Ala-Pro-Leu-Pro-; by subtraction, the first 3 residues of chain B could be deduced to be H-Gly-Leu-Glu-. EC50 was ca 0.3 ng/ml or 10 pM in our in vitro pituitary cell culture assay. Antibodies to residues 1-6 were raised which could immunoneutralize purified inhibin activity in an in vitro assay.
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007265:Inhibins / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification*; D006080:Ovarian Follicle / Q000032:analysis*; D011817:Rabbits; D013552:Swine
D007265:Inhibins