Isohormones of chorionic gonadotropin produced by cloned cell lines in culture.

Abstract

Chorionic gonadotropin (CG) synthesized by human choriocarcinoma cells in culture was fractionated by isoelectric focusing on polyacrylamide gel and examined for biological (B) and immunological (I) activity. Two isohormones of CG with isoelectric points (pI's) of 3.0 and 4.5 were found in the culture medium from each of three clonal lines studied. The isohormones of CG with pI 3.0 had a B/I ratio of 2.5 while the isohormone with pI 4.5 had a B/I ratio of 0.5. The relative proportions of these two isohormones correlated with the B/I ratios previously found for the unfractionated CG from the same clones.