Preparation of conjugates of progesterone with bovine serum albumin in the reversed micellar medium.

Progesterone-BSA (bovine serum albumin) conjugates which contain up to 47 steroid molecules linked to a BSA molecule have been prepared by the activated ester method, the conjugation step being carried out in reversed micellar solutions of sodium di(2-ethylhexyl) sulphosuccinate (AOT) in octane. The number of incorporated steroid molecules increases on passing to increased water/AOT ratios at the given activated steroid/BSA ratio. The results show that the reversed micellar medium would be useful for preparation of conjugates of hydrophobic steroids with proteins in respect to simplicity and ease in obtaining conjugates with high steroid/protein ratios.