Sánchez Ignacio Enrique
Fundacion Instituto Leloir, Buenos Aires, Argentina.
Protein Sci. 2008 Jan;17(1):183-6. doi: 10.1110/ps.073217708.
We propose a new way to characterize protein folding transition states by (1) insertion of one or more residues into an unstructured protein loop, (2) measurement of the effect on protein folding kinetics and thermodynamics, and (3) analysis of the results in terms of a rate-equilibrium free energy relationship, alpha(Loop). alpha(Loop) reports on the fraction of molecules that form the perturbed loop in the transition state. Interpretation of the changes in equilibrium free energy using standard polymer theory can help detect residual structure in the unfolded state. We illustrate our approach with data for the model proteins CI2 and the alpha spectrin SH3 domain.
我们提出了一种表征蛋白质折叠过渡态的新方法，具体如下：（1）将一个或多个残基插入无结构的蛋白质环中；（2）测量其对蛋白质折叠动力学和热力学的影响；（3）根据速率-平衡自由能关系α(Loop)对结果进行分析。α(Loop)反映了在过渡态中形成受扰环的分子比例。利用标准聚合物理论解释平衡自由能的变化，有助于检测未折叠状态下的残余结构。我们用模型蛋白CI2和α-血影蛋白SH3结构域的数据来说明我们的方法。
