Interactions involved in the gelation of bovine serum albumin

The thermal and structural properties of bovine serum albumin (BSA) were studied at different pH values, at different NaCl, lactose, sucrose, and glucose concentrations, and in the presence of cysteine, urea, NEM, and SDS. Maximum thermal stability was observed at pH 5. Glucose had a greater stabilizing effect on the thermal denaturation of BSA than sucrose. Denaturation of BSA resulted in the loss of the 1654 cm(-1) band attributed to alpha-helical structure and the rise of two bands at 1616 and 1684 cm(-1) attributed to the formation of ordered non-native beta-sheet structure associated with aggregation. SDS markedly increased the thermal stability of BSA and prevented aggregate formation. The greatest unfolding on heat treatment was observed in the presence of cysteine and the least in SDS.