Properties of the Subunits of Human Chorionic Gonadotropin^*

Abstract

The preparation and properties of hCG and its subunits hCGα and hCGβ (CR115, CR117 and CR119) are described. The subunits were dissociated in urea and separated on DEAE-Sephadex A-25 followed by further purification on Sephadex G-100. The purity of the subunit preparations has been assessed by SDS-polyacrylamide gel electrophoresis, bioassay, and radioimmunoassay. The biological activities of these subunit preparations are less than 1% of the native hCG. Gel electrophoresis indicates that they are contaminated with less than 2% by weight of the complementary subunit. E 1%280nm values for hCG, hCGα and hCGβ)are 3.6,4.3 and 2.1, respectively; the respective molar extinction coefficients (€) are 1.41 × 104, 0.64 × 104 and 0.56 × 104 M−1 cm−1. (Endocrinology94: 1601, 1974)