A purification procedure for the sex steroid-binding protein of human serum is described. The procedure is significantly superior to that recently published (K. E. Mickelson, D. C. Teller, and P. H. P&a, 1978, Biochemistry 17, 1409-1415) and should replace it for the routine preparation of homogeneous protein in relatively larger quantities. The steps involved diethylaminoethyl-cellulose chromatography, affinity chromatography on 5adihydrotestosterone-17a-hexanyldiaminoethyl-(l,4-butanediol diglycidyl ether)-agarose, and preparative polyacrylamide gel electrophoresis. The most important difference between this new procedure and that previously published is the affinity adsorbent with contains the steroid covalently linked at the 17o-position rather than the 17P-position. This modification allows the purification of at least 12 mg of homogeneous protein per preparation with a 63% total yield. The properties of the homogeneous protein are the same as previously described.
For several years this laboratory has been between 4 and 34%. This communication interested in establishing protein models to describes a modified procedure for the study the phenomenon of steroid-protein purification of the human protein that allows interaction (1). To this end, we have chosen one to circumvent these yield problems the sex steroid-binding protein (SBP)* of and permits the isolation of larger amounts human and rabbit sera as models and have of protein. published procedures to purify them (2,3).