SPECIES DEPENDENCY OF THE LIQUID-CHROMATOGRAPHIC PROPERTIES OF SILICA-IMMOBILIZED SERUM ALBUMINS

A series of chemically bonded serum albumins from different animal sources (i.e., bovine, human, sheep, and pig) have been prepared via a three-step procedure. Subsequently, the differences in the amino acid residues forming the binding pockets for L-tryptophan and related analogues (subdomain mil) were investigated using liquid chromatography. Even though there is a high homology among the different species of serum albumins obtained from a number of animal sources, single changes in the relevant sequence were found to significantly alter the proteins' binding selectivity. Van't Hoff plots for both the L- and the D-enantiomers show expected properties. However, changes in the amino acid sequence are reflected in changes of the specific binding/chromatographic selectivity for differently substituted L-tryptophans.