Affinity chromatographic purification of serum retinol-binding protein using 4-substituted aminoretinoids

Retinol-binding protein has been purified from rabbit serum by a new affinity chromatographic phase. Human retinol-binding protein has been shown to bind with vitamin A derivatives and certain other terpenoids. Consequently, this affinity method is based upon the ability of the protein to reversibly bind to beta-ionone and employs a derivatized affinity ligand while preserving the integrity of the beta-ionone molecule via substitution of the allylic 4-position. Purification is relatively simple when compared with other known methods and the yield from serum is similar to other schemes. The protein is obtained in the apo-form and retains the ability of the native protein to bind retinol.