Effect on immunoreactivity of gonadotropin releasing hormone (GnRH) in the GnRH-BSA conjugates of variable stoichiometry.

In order to render hypothalamic 'self' decapeptide GnRH immunogenic, the GnRH and its azotized derivative were covalently coupled to the carrier protein, BSA. The azotization at histidine and or tyrosine of GnRH was carried out and characterized extensively. Three different molar ratios of GnRH/azo-GnRH with BSA were prepared and characterized by physico-chemical techniques. The conjugates purified by gel-filtration chromatography on G-100 and on gel permeation column using HPLC were subjected to molar ratio determination by amino acid analysis. The immunoreactivity of GnRH/azo-GnRH towards monoclonal and polyclonal antibodies was drastically hampered after conjugation. It is therefore suggested that in the GnRH-carrier conjugate, GnRH concentration should be determined carefully by using specific radioimmunoassay.