Sochava I V, Smirnova O I
Mol Biol (Mosk). 1993 Mar-Apr;27(2):348-57.
Absolute values of heat capacity for some hydrated globular proteins (11S globulin, ovalbumin, ribonuclease A, and lysozyme) have been studied by differential scanning calorimetry. It has been found that for proteins with bound water, as in the case of protein solutions, the heat capacity of denatured proteins is higher then prior to denaturation. Depending on temperature and humidity, the denatured proteins can be either in high-elastic or glass state. Specific heat capacities for these two states have the same values for all proteins and depend only on temperature with a characteristic increment of 0.55 J.g-1.K-1 at glass transition. The glass transitions were observed not only in denatured but also in native proteins. Our results indicate that the main contribution to the heat capacity increment at denaturation is connected with the thermal motion in the protein globule, which is contrast with the commonly accepted ideas.
通过差示扫描量热法研究了一些水合球状蛋白质（11S球蛋白、卵清蛋白、核糖核酸酶A和溶菌酶）的热容绝对值。已发现，对于结合了水的蛋白质，如在蛋白质溶液的情况下，变性蛋白质的热容高于变性前。根据温度和湿度，变性蛋白质可以处于高弹性或玻璃态。这两种状态的比热容对所有蛋白质都具有相同的值，并且仅取决于温度，在玻璃化转变时具有0.55 J·g⁻¹·K⁻¹的特征增量。不仅在变性蛋白质中，而且在天然蛋白质中也观察到了玻璃化转变。我们的结果表明，变性时热容增加的主要贡献与蛋白质球体内的热运动有关，这与普遍接受的观点相反。
