| Abstract: | The effects of attaching a hydrophobic amino acid residue, valine, to the ?-amino groups (lysine residues) of bovine serum albumin (BSA) on the physicochemical and functional properties were assessed. The valyl groups were attached using an N-carboxyvaline anhydride derivative. The valine content of BSA was increased from 27 mol mol?1 protein to 47·91 or 53·72 mol mol?1. The number of lysine residues acylated was dependent on the pH of the reaction mixture as was the degree of polyvalylation. Attachment of polyvalyl chains resulted in improved whipping and gelling properties compared with a control sample of ultrafiltered BSA, and interfered with the formation of α-helices. Hydrophobicity measurements using the fluorescent probe cis-parinaric acid revealed increased hydrophobicity values only after the modified samples had been heat denatured. |
