Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

Abstract

Abstract:Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation of enzyme activity is attributed to its conformational modifications. This review comprehensively addresses the stability and activity of the intact enzymes in various non-aqueous systems, such as organic solvents, ionic liquids, sub-/super-critical fluids and their combined mixtures. It has been revealed that critical factors such as Log P, functional groups and the molecular structures of the solvents define the microenvironment surrounding the enzyme molecule and affect enzyme tertiary and secondary structure, influencing enzyme catalytic properties. Therefore, it is of high importance for biocatalysis in non-aqueous media to elucidate the links between the microenvironment surrounding enzyme surface and its stability and activity. In fact, a better understanding of the correlation between different non-aqueous environments and enzyme structure, stability and activity can contribute to identifying the most suitable reaction medium for a given biotransformation.

Optimization of a protease extraction using a statistical approach for the production of an alternative meat tenderizer fromSpondias cytherearoots

“…This is because hydrophilic solvents have a greater tendency to “strip” tightly bound water from the enzyme molecules surface, which is essential for enzyme catalytic activity, leading to the decrease of the enzyme activity. In addition, it has been demonstrated from a previous study that the enzyme has higher activity and stability in nonpolar (hydrophobic) than polar (hydrophilic) solvents (Wang et al, ). In this study, it can be observed that the highest relative activity was obtained at incubation with cyclohexane > dichloromethane > acetone > methanol (Figure c).…”

Enzymatic Hydrolytic Resolution of Racemic Ibuprofen Ethyl Ester Using an Ionic Liquid as Cosolvent

“…Enzymatic hydrolysis of racemic ibuprofen ethyl ester usually requires a long reaction time (over 24 h) to achieve the maximum yield in both aqueous and organic solvents [31,34,35]. However, the maximum conversion degree, enantiomeric excess of product and enantioselectivity of enzyme were achieved after only 10 …”

“…ILs have unique properties that make them useful as green solvents for many biocatalytic reactions [8,9]. They are non-volatile, non-flammable, and have excellent chemical and thermal stability, which can provide enzymes with excellent levels of activity, stability, and stereoselectivity [10,11]. For enzyme catalysis, the activity and stability of enzymes are closely related to the physicalchemical properties of ILs (e.g., polarity, viscosity, hydrogen bond basicity, hydrophobicity and anion concentration) [12].…”

How to Lengthen the Long-Term Stability of Enzyme Membranes: Trends and Strategies

“…This effect has been applied to enhancing properties such as enzyme activity, heat tolerance, and pH stability [28][29][30][31][32][33][34][35][36][37][38]. Figure 2 shows one example of modified enzymes and schematic illustration of its' enhancing mechanism.…”

“…In addition, new instances of enzyme stability in non-aqueous media such as ionic liquids have been found. Wang et al reviewed concisely enzyme stability and activity in non-aqueous reaction systems [38]; this review deals with the structure and activity of enzymes in non-aqueous media such as organic solvents and ionic liquids. From the above points, it is apparent that modification by amphiphilic molecules retains enzyme structure.…”