Isolation of Human Grchth Hormone Iscrcrmcnes D and E In Milligram Amounts (I), Using I Sotachophoeesis CN Polyacrylam Ide Gel

Abstract

Human growth hormone (hGH) isohormones D and E were isolated from a plasmln digest of 150 mg hGH. Isotachophoresis on a cylindrical polyacry lamide pei of 18 mm diameter served to separate the various isohcrvone species. The “extended stack” was sliced, and slices containing hGH-D and -E were extracted by Steady-State Stacking on 1% agarose gel and collected in a 1 ml volume. The extract was purified on gel chromatography and lyophllized. The overall yield was approximately 19 mg of hGH- (D+E) and 16 rag of hGH-(D. minor E). This represents a 62% recovery of the amount of hGH-D and -F in the digest estimated densitometrically. The purity of the product, baaed on Lowry analysis, specific RIA or UV-absorbance, (as 91∗. The isolated hCH-(D+E) exhibited an enhanced bioactivlty in the rat tibia line assay.