Department of Chemistry, University of Delhi, Delhi, 110 007, India.
Phys Chem Chem Phys. 2020 Nov 14;22(42):24410-24422. doi: 10.1039/d0cp04397d. Epub 2020 Oct 21.
Proteins have immense untapped potential in numerous industries as a green catalyst. Thus, there is an emergent need to find a suitable co-solvent which is biocompatible with proteins and environmentally safe. In this context, the present study investigates the effect of a novel solvent medium designed by an amalgamation of macromolecular crowders and deep eutectic solvents (DESs) on bovine serum albumin (BSA). It was discovered that the presence of crowding agents such as polyethylene glycol (PEG) 12 kDa (P12), 20 kDa (P20), and Ficoll 70 kDa (F70) marginally destabilizes the conformational stability of BSA. While the thermal stability of BSA was dramatically enhanced in the presence of choline chloride (ChCl)-based deep eutectic solvents (DESs) namely ChCl-urea (DES1) and ChCl-glycerol (DES2), the order of stability was (DES1) > (DES2). It was interesting to note that DES1 possessing urea as a hydrogen bond donor leads to the exceptional thermal stability of the BSA structure. Taking a cue from this, an innovative crowded DES medium was prepared by mixing a synthetic crowder and DES1 in optimum concentration. Fascinatingly, the combination of DES1 with PEG delivers promising results, as they elevate the thermal stability of BSA by approximately 16 °C. Thus, crowded DES medium confers structural compactness to the BSA. Altogether, this work reports for the first time the potential of DESs to attenuate the adverse effects of macromolecular crowding on protein stability.
蛋白质作为一种绿色催化剂，在众多行业中具有巨大的未开发潜力。因此，迫切需要找到一种合适的共溶剂，这种溶剂既要与蛋白质具有生物相容性，又要对环境安全。在这种情况下，本研究调查了由大分子拥挤剂和深共熔溶剂（DESs）混合物设计的新型溶剂介质对牛血清白蛋白（BSA）的影响。研究发现，存在聚乙二醇（PEG）12 kDa（P12）、20 kDa（P20）和 Ficoll 70 kDa（F70）等拥挤剂会轻微破坏 BSA 的构象稳定性。虽然在氯化胆碱（ChCl）基深共熔溶剂（DESs），即 ChCl-尿素（DES1）和 ChCl-甘油（DES2）存在的情况下，BSA 的热稳定性显著增强，但稳定性的顺序为（DES1）>（DES2）。有趣的是，DES1 中含有作为氢键供体的尿素，导致 BSA 结构具有异常的热稳定性。由此得到启示，通过混合合成拥挤剂和 DES1 制备了新颖的拥挤 DES 介质。令人惊讶的是，DES1 与 PEG 的组合产生了有希望的结果，因为它们使 BSA 的热稳定性提高了约 16°C。因此，拥挤 DES 介质使 BSA 结构更加紧凑。总之，这项工作首次报道了 DESs 具有减轻大分子拥挤对蛋白质稳定性的不利影响的潜力。
