Structure and ligand binding properties of human serum albumin.

Abstract

Single binding of ligands to serum albumin is usually described as high-affinity binding to one or two sites and weaker binding to a larger number of sites. In this chapter, the original binding model for high-affinity binding is elaborated. Region 1 seems to be specific for binding of one, or possibly two, ions of long-chain fatty acids. Region 2 is somewhat less specific and includes binding of octanoate, tryptophan, chlorazepate, thyroxine, p-iodobenzoate and possibly also chloride. Region 3 accommodates bilirubin, Phenol Red, Bromophenol Blue and iopanoate. Region 4 is a special site for strong binding of metal ions such as Cu++ and Ni++. Evidence is presented for placing the primary haemin site in a separate region (no. 5). The existence of additional binding regions, well-suited for high-affinity binding of drugs, is discussed...