PRODUCTION OF A HORMONE RECEPTOR COMPETITIVE ANTAGONIST

RECENT RESEARCH IN REPRODUCTIVE ENDOCRINOLOGY HAS DEMONSTRATED THE IMPORTANCE OF FOLLICLE STIMULATING HORMONE (FSH) IN THE REGULATION OF GAMETOGENESIS AND GONADAL STEROIDPRODUCTION. IT HAS BEEN SHOWN THAT N-LINKED OLIGOSACCHARIDES, ATTACHED TO ASPARAGINE RESIDUES AT SPECIFIC SITES ALONG THE MOLECULE, ARE ESSENTIAL FOR POST-RECEPTOR TARGET CELL ACTIVATION BUT NOT RECEPTOR BINDING. THESE SUGARS ALSO PLAY A ROLE IN DETERMINING THE HALF-LIFE OF THE MOLECULE IN CIRCULATION. WE PLAN TO USE THE TECHNIQUE OF SITE-DIRECTED MUTAGENESIS TO PRODUCE A RECOMBINANT HUMAN FSH MOLECULE THAT WILL HAVE ONE OR MORE OFTHE ASPARAGINE RESIDUES REPLACED WITH A SIMILARLY CHARGED AMINO ACID TO "ERASE" THE SITE OF N-LINKED SUGAR ATTACHMENT.PRELIMINARY STUDIES HAVE SHOWN THAT REMOVAL OF SUGARS FROM THE ALPHA CHAIN SEVERELY DECREASE BIOLOGIC ACTIVITY. REMOVAL OF THESE SUGAR RESIDUES, BY MUTAGENESIS, WILL PRODUCE A LONG ACTING COMPETITIVE ANTAGONIST OF FSH, WHICH, WHEN ADMINISTERED TO HUMANS, WOULD BE EXPECTED TO RESULT IN AN ANOVULATORY STATE OR AZOSPERMIA. A MUTAGENIZED, RECOMBINANT HORMONE MAY BE PRODUCED IN LARGE AMOUNTS, WITH EACH BATCH EXHIBITING UNIFORM BIOCHEMICAL AND BIOLOGICAL PROPERTIES. THEREFORE, THIS PRODUCT WOULD BE AN EXCELLENT CHOICE AS A REVERSIBLE CONTRACEPTIVE IN MEN AND WOMEN.