Effect of acetylation on conformation and bilirubin-binding properties of goat serum albumin.

Four acetylated derivatives of goat serum albumin with percentage modifications of 18, 40, 53 and 93% were checked for bilirubin-binding and conformational properties. Acetylation caused marked changes in protein conformation, as evidenced by double immunodiffusion and proteolytic digestion results, as well as a decrease in bilirubin binding. An increase in ionic strength had a dramatic effect on the bilirubin-binding characteristics of modified proteins. The results suggest that the lysine residues of goat serum albumin modified in this study are not involved in bilirubin-albumin interaction.