Hinz H J, Filimonov V V, Privalov P L
Eur J Biochem. 1977 Jan 3;72(1):79-86. doi: 10.1111/j.1432-1033.1977.tb11226.x.
The heat effects involved in thermal unfolding of tRNAPhe from yeast have been determined in various buffer systems by direct differential scanning calorimetry. Perfect reversibility of the melting process has been demonstrated for measurements in the absence of Mg2+ ions. The overall molar transition enthalpy, delta Ht = 298 +/- 15 kcal mol-1 (1247 +/- 63 kJ mol-1), has been shown to be independent of the NaCl concentration and the nature of the buffers used in this study. Delta Ht is identical in the presence and in the absence of Mg2+ ions within the margin of experimental error. This experimental result implies a vanishing or very small heat capacity change to be associated with melting. Decomposition of the calorimetrically determined complex transition curves, on the assumption that the experimental melting profile represents the sum of independent two-state transitions, results in five transitions which have been assigned to melting of different structural domains of the tRNA.
通过直接差示扫描量热法，已在各种缓冲系统中测定了酵母苯丙氨酸转运核糖核酸（tRNAPhe）热解折叠过程中的热效应。对于在不存在Mg2+离子的情况下进行的测量，已证明熔解过程具有完美的可逆性。总摩尔转变焓，ΔHt = 298±15千卡/摩尔（1247±63千焦/摩尔），已表明与本研究中使用的NaCl浓度和缓冲液的性质无关。在实验误差范围内，存在和不存在Mg2+离子时的ΔHt相同。该实验结果意味着与熔解相关的热容变化消失或非常小。假设实验熔解曲线代表独立的两态转变之和，对量热法测定的复杂转变曲线进行分解，得到五个转变，这些转变已被归因于tRNA不同结构域的熔解。
