Interaction between Bovine Serum Albumin and Saponin As Studied by Heat Stability and Protease Digestion

Soyasaponins were added to bovine serum albumin (BSA), and the interaction between BSA and soyasaponin was studied by heat stability and protease digestion. Results from enzyme-linked immunosorbent assays and circular dichroism spectra showed that the heat stability of BSA was increased by soyasaponin addition. Furthermore, results from α-chymotrypsin digestion showed that BSA's susceptibility to α-chymotrypsin digestion was decreased by soyasaponin addition and that the N-terminal 26 kDa peptide fragment obtained from the hydrolysate of BSA−soyasaponin complex interacted with soyasaponin to form a protease-resistant moiety that is low in sensitivity to α-chymotrypsin.