Abstract
The thermal denaturation (N-D transition) of fatty acid-containing and defatted (fatty acid-free) bovine serum albumin (BSA) at pH 7.00 was investigated by differential scanning microcalorimetry. The enthalpy change (ΔHcal) associated with the thermal transition from the native to the denatured state for the fatty acid-free BSA was about 30% lower than that for the fatty acid-containing BSA. The calorimetric data of two BSA's were analyzed on the basis of a double deconvolution method proposed by S. Kidokoro et. al. (Biopolymers 26, 231 (1987)). By this method, the thermal transition of the defatted BSA was analyzed to be a three-state transition, while the thermal transition of the fatty acid-containing BSA was estimated to be a four-state transition, corresponding to a three-domain structural model for this protein.
