PURIFICATION AND CHARACTERIZATION OF HUMAN SEX-HORMONE BINDING GLOBULIN

Sex hormone binding globulin (SHBG) was isolated from post-partum plasma in a three stage procedure involving affinity chromatography on androstanediol-3-hemisuccinate aminohexyl Sepharose 4B followed by affinity chromatography using Cibacron Blue F3G-A-Sepharose 4B and finally gel filtration on Sephadex G-150. The purified protein was homogeneous in polyacrylamide gel electrophoresis and had retained its binding activity for 5α-dihydrotestosterone (5α-DHT) with 1.08 binding site per mol. The procedure yielded 5mg of protein with an overall purification of about 3700. The association constant for 5α-DHT at 4°C was 0.6 × 109L/M; the molecular weight based on sodium dodecyl sulphate polyacrylamide gel electrophoresis was 80,000 and the latter technique also demonstrated four components of almost identical mobilities. Amino acid and carbohydrate compositions were determined for the purified protein. © 1979.