Recent advances in exploiting ionic liquids for biomolecules: Solubility, stability and applications

Abstract

The technological utility of biomolecules (e.g. proteins, enzymes and DNA) can be significantly enhanced by combining them with ionic liquids (ILs) - potentially attractive "green" and "designer" solvents - rather than using in conventional organic solvents or water. In recent years, ILs have been used as solvents, cosolvents, and reagents for biocatalysis, biotransformation, protein preservation and stabilization, DNA solubilization and stabilization, and other biomolecule-based applications. Using ILs can dramatically enhance the structural and chemical stability of proteins, DNA, and enzymes. This article reviews the recent technological developments of ILs in protein-, enzyme-, and DNA-based applications. We discuss the different routes to increase biomolecule stability and activity in ILs, and the design of biomolecule-friendly ILs that can dissolve biomolecules with minimum alteration to their structure. This information will be helpful to design IL-based processes in biotechnology and the biological sciences that can serve as novel and selective processes for enzymatic reactions, protein and DNA stability, and other biomolecule-based applications.

Proteins in Ionic Liquids: Current Status of Experiments and Simulations

“…Various salts including , , , and others also have been tested [112] but combined a high solubility in water with an excellent ability to promote phase separation with the ionic liquid. These two-phase systems are distinguished by their protein selectivity, robustness, short processing time, low energy consumption and easy scale up opportunities [108, 113]. Cation [101] and anion [104] effects have been studied by the Coutinho group.…”

“…This area of applications is reviewed elsewhere [16, 32, 57, 113] in more detail and only briefly summarized here: they may chemically modify the protein or stabilize a (genetic) protein modification or immobilize the protein at a surface for chemical reactions [32]. Because of their tunable properties, particular ionic liquids are capable to selectively solubilize reactions and/or products, which offers in two-phase systems better product separation and improved recoverability of the catalyzing protein (as discussed in the Sect.…”

“…In contrast to classical polar organic solvents some polar ionic liquids seem to activate particular proteins [32, 113, 120, 139], whereas the activity of another enzymes is diminished [32, 37, 113, 140]. One has to bear in mind that reaction rates in different ionic liquids are usually compared at the same amount of water.…”

An Overview on the Toxicological Properties of Ionic Liquids toward Microorganisms

“…This is why they easily migrate into the environment and affect living biota. Therefore, there is valid expectation that the toxicity of ILs be determined before they are considered for any applications . In recent years, the cytotoxicity, eco‐toxicity, and microbial toxicity of ILs have been studied extensively.…”

Green Composites from Ionic Liquid-Assisted Processing of Sustainable Resources: A Brief Overview

“…The strong interand intramolecular hydrogen bonding and the highly recalcitrant nature of the biopolymers and lignocellulose offer a critical challenge to extend the novel applications of these materials in composite industries [16,17]. In this regard, various pretreatment technologies were developed to reduce the recalcitrance of lignocellulosic polymers, which apply chemical or hydrothermal treatments after mechanical comminution.…”