Scalley M L, Baker D
Department of Biochemistry 357350, University of Washington, Seattle, WA 98195, USA.
Proc Natl Acad Sci U S A. 1997 Sep 30;94(20):10636-40. doi: 10.1073/pnas.94.20.10636.
The anomalous temperature dependence of protein folding has received considerable attention. Here we show that the temperature dependence of the folding of protein L becomes extremely simple when the effects of temperature on protein stability are corrected for; the logarithm of the folding rate is a linear function of 1/T on constant stability contours in the temperature-denaturant plane. This convincingly demonstrates that the anomalous temperature dependence of folding derives from the temperature dependence of the interactions that stabilize proteins, rather than from the super Arrhenius temperature dependence predicted for the configurational diffusion constant on a rough energy landscape. However, because of the limited temperature range accessible to experiment, the results do not rule out models with higher order temperature dependences. The significance of the slope of the stability-corrected Arrhenius plots is discussed.
蛋白质折叠的异常温度依赖性已受到广泛关注。在此我们表明,当校正温度对蛋白质稳定性的影响时,蛋白质L折叠的温度依赖性变得极其简单;在温度-变性剂平面的恒定稳定性等高线上,折叠速率的对数是1/T的线性函数。这令人信服地证明,折叠的异常温度依赖性源于稳定蛋白质的相互作用的温度依赖性,而非源于在粗糙能量景观上构型扩散常数所预测的超阿仑尼乌斯温度依赖性。然而,由于实验可及的温度范围有限,这些结果并未排除具有高阶温度依赖性的模型。文中讨论了稳定性校正后的阿仑尼乌斯图斜率的意义。