Purification of rat retinol-binding protein using Blue Sepharose CL-6B.

Studies were conducted to isolate rat plasma retinol-binding protein, the specific transport protein for vitamin A in the rat. Retinol-binding protein was isolated from rat plasma by a new simple procedure using Blue Sepharose CL-6B, and highly purified retinol-binding protein was obtained. This procedure included DEAE-cellulose chromatography at pH 6.0, Sephadex G-75 gel filtration in the presence of 3.0 M urea, Blue Sepharose CL-6B affinity chromatography at pH 7.0 and finally Sephadex G-100 gel filtration at pH 7.4. The third step completely accomplished the dissociation and separation of retinol-binding protein from its complex with prealbumin and plasma albumin. This procedure is a significant improvement over previously published procedures, in which sample recycling and preparative polyacrylamide gel electrophoresis are necessary. The molecular weight, electrophoretic behaviour, ultraviolet and fluorescence spectra of the retinol-binding protein were similar to those appearing in other reports.