Zhou Huan-Xiang
Department of Physics and Institute of Molecular Biophysics and School of Computational Science, Florida State University, Tallahassee, FL 32306, USA.
Proteins. 2008 Sep;72(4):1109-13. doi: 10.1002/prot.22111.
In cells, proteins fold and unfold in the presence of macromolecules with various sizes and shapes. Recent experiments by Liang and coworkers (J Biol Chem 2004;279:55109-55116; J Mol Biol 2006;364:469-482) show that protein refolding is enhanced by a mixture of two different crowding agents relative to the individual crowding agents and an optimal mixing ratio exists. Here, we present a theory that predicts the existence of an optimal mixing ratio. The theory is based on models for calculating the changes in the chemical potentials of the folded and unfolded states by a mixture of crowders. The existence of an optimal mixing ratio results from the dependences of these chemical-potential changes on crowder sizes and concentrations, which can be argued to be quite general. We further predict that, for any crowding agent, the stabilizing effect can be optimized both by varying the molecular weight and the mixing ratio of two species with different molecular weights.
在细胞中，蛋白质在存在各种大小和形状的大分子的情况下折叠和展开。梁及其同事最近的实验（《生物化学杂志》2004年；279:55109 - 55116；《分子生物学杂志》2006年；364:469 - 482）表明，相对于单个拥挤剂，两种不同拥挤剂的混合物可增强蛋白质重折叠，且存在一个最佳混合比例。在此，我们提出一种理论，预测最佳混合比例的存在。该理论基于通过拥挤剂混合物计算折叠态和未折叠态化学势变化的模型。最佳混合比例的存在源于这些化学势变化对拥挤剂大小和浓度的依赖性，这种依赖性可被认为是相当普遍的。我们进一步预测，对于任何拥挤剂，通过改变分子量以及两种不同分子量物种的混合比例，都可以优化稳定效果。
