Follicle stimulating hormone-glycosylation analogs

A DNA molecule comprising a recombinant expression system capable, when transformed into a recombinant host cell, of expressing a gene encoding a mutein of the human gonadotropin alpha subunit which mutein, when combined with a beta gonadotropin subunit results in a modified gonadotropin hormone which is an antagonist to the corresponding native gonadotropin hormone

• which expression system comprises an oligonucleotide sequence encoding a human alpha subunit mutein lacking through deletion or alteration one or more of amino acids 88-92 of the native subunit operably linked to control sequences functional in said host cell.