Triazine dye binding of human alpha-fetoprotein and albumin

Column chromatography was used to investigate the interaction of human alpha-fetoprotein and albumin with different immobilized dyes. Binding of alpha-fetoprotein to the dye conjugates was studied at pH 7.0. Between 56 and 93% of the total alpha-fetoprotein applied to the column was recovered in the break-through fractions of the respective runs. Of all the dyes, Cibacron Blue F3G-A adsorbs alpha-fetoprotein most strongly. This interaction clearly depends on the degree of dye substitution of the gel. A relatively weak interaction exists between alpha-fetoprotein and immobilized Procion Red HE-3B. This is used in the purification of alpha-fetoprotein by negative chromatography resulting in a 16.6-fold enrichment of this protein. Human albumin binds tightly to immobilized Cibacron Blue F3G-A as well as to Cibacron Brilliant Blue FBR-P and shows a lower affinity to Procion Blue MX-R. Procion Red dyes, which are structurally different from Cibacron Blue F3G-A are also capable of interacting with serum albumin. The results obtained are discussed in terms of the present theoretical conceptions about dye-protein interactions.