Isolation of human growth hormone isohormones D and E in milligram amounts (II), using isoelectric focusing on polyacrylamide gel.
Human growth hormone (hGH) isohormones D and E were prepared from a partial enzymatic hydrolyzate catalyzed by plasmin, using isoelectric focusing on polyacrylamide gel to fractionate the digest. Separation between the two isohormones species was optimized by employing a maximally flattened pH gradient between pH's 4.3 and 5.6. Gel slices containing isohormones D and E were extracted and concentrated by Steady-State Stacking on polyacrylamide gel. The extract was purified by gel filtration and lyophilized. Overall yields of lyophilized isohormones D and E were 10.9 mg and represented a recovery of 51% relative to the densitometrically estimated isohormone concentrations in the hGH digest. Purity of the products, based on Lowry analysis, U.V. absorbance and radioimmunoassay (RIA) was 60-70%. The isolated isohormone species were active in the rat tibia-line assay and in the specific RIA for hGH.
D000180:Acrylic Resins; D000818:Animals; D001681:Biological Assay; D002850:Chromatography, Gel; D005341:Fibrinolysin; D005782:Gels; D013006:Growth Hormone / Q000302:isolation & purification*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing / Q000379:methods; D008832:Microchemistry / Q000379:methods; D010446:Peptide Fragments / Q000302:isolation & purification*; D011863:Radioimmunoassay; D051381:Rats; D013056:Spectrophotometry, Ultraviolet
D000180:Acrylic Resins; D005782:Gels; D010446:Peptide Fragments; C030484:human growth hormone isohormone D; C030485:human growth hormone isohormone E; C016680:polyacrylamide gels; D013006:Growth Hormone; D005341:Fibrinolysin