ISOLATION AND CHARACTERIZATION OF OVINE FOLLICLE STIMULATING HORMONE

A method is described for the preparation of a homogeneous ovine follicle stimulating hormone. The procedures involve an initial extraction of fresh frozen pituitary glands with a urea solution and fractionation by variations of pH and (NH4)2SO4 concentrations. Final purification is achieved by zone electrophoresis on a Sephadex G-25 column. The purified follicle stimulating hormone is shown to be homogeneous by starch-gel electrophoresis, moving boundary electrophoresis, sedimentation velocity and sedimentation equilibrium studies. The following physical constants have been determined: isoelectric pH, 4.4; s°20,w, 3.5·10-13 sec; D°20,w, 10.14·10-7 cm2/sec; v, 0.70 ml/g. The weight average molecular weight was calculated to be 32 095. Analyses of individual amino acids and carbohydrates associated with this follicle stimulating hormone are reported. The follicle stimulating activity of this preparation is approx. 43 times that of the NIH-FSH-S1 standard and it appears to be free of interstitial cell stimulating hormone activity. © 1968.