Partition of purified human thyroxine-binding globulin in aqueous two-phase systems in response to reactive dyes.
Thyroxine-binding globulin was isolated from pooled human serum by a two-step method involving affinity chromatography on thyroxine-Sepharose and preparative disc-electrophoresis. The final product was found to be homogeneous by polyacrylamide gel electrophoresis and has a molecular weight of 59,000. Isoelectric focusing resolved the protein into seven bands with isoelectric points ranging from 3.9 to 4.3. The isolated protein showed affinity to a number of different dyes as recognized by affinity phase partitioning. The interaction of the protein with the dye Cibacron Blue F3G-A was found to be strongly competitive with the natural ligand thyroxine.
D000418:Albumins / Q000302:isolation & purification; D002846:Chromatography, Affinity; D004396:Coloring Agents; D004589:Electrophoresis, Disc; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D012965:Sodium Chloride / Q000032:analysis; D013974:Thyroxine / Q000032:analysis; D013975:Thyroxine-Binding Proteins / Q000302:isolation & purification*
D000418:Albumins; D004396:Coloring Agents; D013975:Thyroxine-Binding Proteins; D012965:Sodium Chloride; D013974:Thyroxine