Nandi Somen, Parui Sridip, Halder Ritaban, Jana Biman, Bhattacharyya Kankan
Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India.
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462 066, India.
Biophys Rev. 2018 Jun;10(3):757-768. doi: 10.1007/s12551-017-0331-1. Epub 2017 Nov 16.
In this review, we give a brief overview on how the interaction of proteins with ionic liquids, alcohols and dimethyl sulfoxide (DMSO) influences the stability, conformational dynamics and function of proteins/enzymes. We present experimental results obtained from fluorescence correlation spectroscopy on the effect of ionic liquid or alcohol or DMSO on the size (more precisely, the diffusion constant) and conformational dynamics of lysozyme, cytochrome c and human serum albumin in aqueous solution. The interaction of ionic liquid with biomolecules (e.g. protein, DNA etc.) has emerged as a current frontier. We demonstrate that ionic liquids are excellent stabilizers of protein and DNA and, in some cases, cause refolding of a protein already denatured by chemical denaturing agents. We show that in ethanol-water binary mixture, proteins undergo non-monotonic changes in size and dynamics with increasing ethanol content. We also discuss the effect of water-DMSO mixture on the stability of proteins. We demonstrate how large-scale molecular dynamics simulations have revealed the molecular origin of this observed phenomenon and provide a microscopic picture of the immediate environment of the biomolecules. Finally, we describe how favorable interactions of ionic liquids may be utilized for in situ generation of fluorescent gold nano-clusters for imaging a live cell.
在本综述中，我们简要概述了蛋白质与离子液体、醇类和二甲基亚砜（DMSO）的相互作用如何影响蛋白质/酶的稳定性、构象动力学和功能。我们展示了通过荧光相关光谱法获得的关于离子液体、醇类或DMSO对水溶液中溶菌酶、细胞色素c和人血清白蛋白的大小（更确切地说是扩散常数）及构象动力学影响的实验结果。离子液体与生物分子（如蛋白质、DNA等）的相互作用已成为当前的一个前沿领域。我们证明离子液体是蛋白质和DNA的优良稳定剂，并且在某些情况下，能使已被化学变性剂变性的蛋白质重新折叠。我们表明，在乙醇 - 水二元混合物中，随着乙醇含量的增加，蛋白质的大小和动力学发生非单调变化。我们还讨论了水 - DMSO混合物对蛋白质稳定性的影响。我们展示了大规模分子动力学模拟如何揭示这一观察到的现象的分子起源，并提供生物分子紧邻环境的微观图像。最后，我们描述了如何利用离子液体的有利相互作用原位生成荧光金纳米团簇用于活细胞成像。
