Abstract: | An extract containing solubilised receptor was passed through four columns containing Sepharose to which had been covalently coupled anti-cobalophilin IgG, vitamin B-12-intrinsic factor, vitamin B-12, and free intrinsic factor, respectively. Following a wash the receptor was eluted with EDTA, then residual Triton X-100 micelles and vitamin B-12-intrinsic factor were removed by Sephadex G-200 filtration. The receptor was purified 84 000-fold, sodium dodecyl sulphate electrophoresis indicated two subunits and gel filtration of its vitamin B-12-inttrinsic factor complex resolved it into two molecular species. |