Antigenic properties of estriol 3-glucuronide-[C-6]-bovine serum albumin conjugates having oxime bridges.

Abstract

The preparation and antigenic properties of estriol 3-glucuronide-bovine serum albumin (BSA) conjugate in which the hapten is linked to the carrier protein through an (O-3-carboxypropylcarbamoylmethyl)oxime bridge at the C-6 position on the steroid nucleus, has been described. 16,17-Di-O-acetyl-6-oxoestriol 6-(O-carboxymethyl)oxime 3-glucuronide acetate-methyl ester was condensed with gamma-amino-n-butyric acid by the mixed anhydride method. Subsequent coupling with BSA followed by removal of the protecting groups with alkali gave the desired hapten-BSA conjugate. The antisera elicited in the rabbit with the conjugate were highly specific to estriol 3-glucuronide, discriminating from other 3-substituted compounds. The specificity of antisera improved by elongation of the 6-(O-carboxymethyl)oxime bridge has been discussed.