Griko Iu V, Ben'iaminov S Iu, Privalov P L
Mol Biol (Mosk). 1992 Mar-Apr;26(2):285-91.
The changes in structure and thermodynamic parameters of beta-lactoglobulin upon heat and cold denaturation have been studied using both scanning microcalorimetry and circular dichroism spectroscopy methods. It has been shown that in contrast to the heat denaturation process, the cold denaturation of beta-lactoglobulin is accompanied by an opposite heat effect. In all cases, the calorimetrically measured enthalpy of beta-lactoglobulin cold denaturation is higher than it was expected from the two-state model of denaturation transition. It has been concluded that beta-lactoglobulin cold denaturation cannot be represented by a transition between two microscopic states--native and denatured. The latter, is due to the additional process that occurs together with the disruption of the beta-lactoglobulin tertiary structure and is accompanied by increasing heat capacity. Taking into account the heat capacity contribution of this process upon calculation of the enthalpy makes it closer to the enthalpy value calculated for the two-state model of denaturation transition.
利用扫描量热法和圆二色光谱法研究了β-乳球蛋白在热变性和冷变性时的结构和热力学参数变化。结果表明，与热变性过程相反，β-乳球蛋白的冷变性伴随着相反的热效应。在所有情况下，量热法测得的β-乳球蛋白冷变性焓均高于变性转变二态模型的预期值。得出的结论是，β-乳球蛋白的冷变性不能用天然态和变性态这两种微观状态之间的转变来表示。后者是由于与β-乳球蛋白三级结构破坏同时发生的额外过程，且该过程伴随着热容增加。在计算焓时考虑该过程的热容贡献，使其更接近变性转变二态模型计算出的焓值。
