Deciphering the role of the thermodynamic and kinetic stabilities of SH3 domains on their aggregation inside bacteria
Deciphering the role of the thermodynamic and kinetic stabilities of SH3 domains on their aggregation inside bacteria
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DOI：
10.1002/pmic.201000260
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发表时间：
2010-12-01
期刊：
影响因子：
3.4
通讯作者：
Ventura, Salvador
中科院分区：
文献类型：
--
作者：
Castillo, Virginia;Espargaro, Alba;Ventura, Salvador
球状蛋白形成不溶沉积是许多人类疾病发生的基础，最近的研究表明，蛋白质的热力学稳定性与它们在体内的聚集之间存在关系，然而，有人认为，在细胞中，不可逆聚集的发生可能会以一种方式改变系统的平衡，即它可能是与之相关的动力学稳定性和相关的动力学稳定性，而不是控制蛋白质沉积的构象稳定性。这是一个重要但难以破译的问题，因为动力学稳定性和热力学稳定性似乎通常是相关的。在这里，我们通过比较一组非自然SH3结构域的体外折叠动力学和稳定性特征与它们的聚集特性来解决这个问题。此外，当在细菌中表达时，我们将分离结构域的体外稳定性与它们在模拟胞浆环境的条件下的有效稳定性进行了比较。这些数据支持对小球状蛋白的细胞内聚集倾向进行热力学控制，而不是动力学控制，在这种情况下，折叠和解折叠速度大大超过聚集速度。这些结果对蛋白质的进化具有重要意义
The formation of insoluble deposits by globular proteins underlies the onset of many human diseases Recent studies suggest a relationship between the thermodynamic stability of proteins and their in vivo aggregation However it has been argued that in the cell the occurrence of irreversible aggregation might shift the system from equilibrium in such a way that it could be the rate of unfolding and associated kinetic stability instead of the conformational stability that controls protein deposition This is an important but difficult to decipher question because kinetic and thermodynamic stabilities appear usually correlated Here we address this issue by comparing the in vitro folding kinetics and stability features of a set of non natural SH3 domains with their aggregation properties when expressed in bacteria In addition we compare the in vitro stability of the isolated domains with their effective stability in conditions that mimic the cytosolic environment Overall the data argue in favor of a thermodynamic rather than a kinetic control of the intracellular aggregation propensities of small globular proteins in which folding and unfolding velocities largely exceed aggregation rates These results have implications regarding the evolution of proteins