Biological studies on the relatedness of subunits of human follicle stimulating hormone and chorionic gonadotropin.

Abstract

A mixture of α- and β-subunits of human follicle stimulating hormone, hFSH (α,β), was prepared by propionic acid treatment of highly purified hFSH (4279 IU/mg). Incubation of hFSH (a,β) (198 IU/mg) under conditions previously shown to favor recombination of FSH subunits resulted in recovery of 24.8% FSH activity (1063 IU/mg). hCG-like activity was 43 IU/mg. When incubation of hFSH (α,β) was carried out in the presence of the αsubunit of hCG, recovery of FSH activity was 81% (3470 IU/mg). hCG-like activity was 89 IU/mg. When incubation of hFSH (α,β) was carried out in the presence of the P-subunit of hCG, recovery of FSH activity was only 12% (515 IU/mg). However, the hCG-like activity increased 93-fold, from 43 IU/mg-4010 IU/mg. These results are interpreted as indicating that biologically active hybrid molecules can be formed between the βsubunit of hFSH and the αsubunit of hCG, and between αsubunit of hFSH and the P-subunit of hCG. Because of this, it is predicted that the a-subunits of hCG and hFSH con...