Comprehensive Evaluation of Biomolecular Interactions between Protein and Amino Acid Based‐Ionic Liquids: A Comparable Study between [Bmim][Br] and [Bmim][Gly] Ionic Liquids

Abstract

Protein is one of the most intricate and overriding biological system. Over the past years, there is an increased demand to consider ionic liquids (ILs) as novel biocompatible co-solvents for proteins.The overwhelming attention grabbed by new-generation ''amino acid ionic liquids (AAILs)''among various fields of modern chemistry and biology, has been attributed to their unique and designer nature. However, the stability of proteins in such AAILs is still untouched. Therefore, we have synthesized 1-butyl-3-methylimidazolium glycine ([Bmim][Gly]) in which anion is directly derived from natural amino acid and characterized to improve the stability of stem bromelain (BM). Since, it is speculated that replacement of cation/anion with the amino acids (AAs) will improve the stability of protein. Therefore, the main aim of present work is to highlight the influence of [Bmim][Gly] on the conformational stability and activity of BM. Furthermore, enzyme's stability and activity arecompared with the conventional imidazolium-based ionic liquid i. e. 1-butyl-3methylimidazolium bromide [Bmim][Br] by using spectroscopic techniques, enzyme assay and molecular docking. Our study shows that both studied ILs interact with functional groups of BM. As a result, in contrast to our expectation it appears that [Bmim] [Br] stabilizes BM more than [Bmim] [Gly]. We believe that present study will provide new insights into the interactions between enzyme and AAILs in the field of protein stabilization.

Microbial Biocompatibility and Biodegradability of Choline-Amino Acid Based Ionic Liquids

“…Cho[Asp] revealed acceptable biocompatibility and on the other hand Cho [Trp] and Cho [Tyr] showed less biocompatibility towards all the tested bacteria. This is due to the presence of an aromatic ring in structure of the anion which leads to higher toxicity to the tested microorganism [50,51].…”

Long-term protein packaging in cholinium-based ionic liquids: improved catalytic activity and enhanced stability of cytochrome c against multiple stresses

“…However, no significant improvements in the catalytic activity of Cyt C was recorded by the authors 26,30,31. On the other hand, it has been suggested that the IL anion exerts a dominating effect on the catalytic activity and stability of enzymes 32. Recently, ILs based on anions derived from carboxylic acids and dicarboxylic acids with high hydrogen-bonding characteristics have been introduced in order to design protein friendly solvent systems 33–38.…”

Enzyme entrapment, biocatalyst immobilization without covalent attachment

“…216,217 Cholinium ILs with different anions, for example amino acids, are emerging as a green and sustainable ionic liquid media for enzyme/protein stability and activity studies. 204,[217][218][219]220,221 Fatty acid [222][223][224][225] and lactam 226,227 based ionic liquids are also likely to significantly contribute towards the library of greener ILs for future industrial biocatalytic processes.…”