Affinity separation of human plasma gelsolin on Affi-Gel Blue

Human plasma gelsolin was specifically eluted with 1 mM adenosine 5'-triphosphate from an Affi-Gel Blue column. Since the ionic strength of sodium chloride required to elute the protein from the dye column was much higher than that of 1 mM adenosine 5'-triphosphate, the binding of plasma gelsolin with the dye-ligand appeared to be biospecific. Taking advantage of this affinity interaction, we have developed a revised purification method of human plasma gelsolin. The purification included ammonium sulfate precipitation, diethylaminoethyl-Sepharose chromatography, Affi-Gel Blue chromatography, and Phenyl-Sepharose chromatography. The method allowed a reproducible purification of the protein to apparent homogeneity, producing a 331-fold purification with a yield of 6%.