Enhancing the Biocatalytic Activity of l-Asparaginase Using Aqueous Solutions of Cholinium-Based Ionic Liquids

Abstract

l-Asparaginase (ASNase) is a high value enzyme for the pharmaceutical and food industries. Although ionic liquids (ILs) have been recognized as promising solvents or additives for biocatalysis, there are very few studies on the effect of ILs on the activation of ASNase. To address this, the enzymatic activity of a commercial ASNase in aqueous ILs was evaluated. ASNase was exposed for up to 24 h to aqueous solutions (0.001–0.050 mol·mol–1) of cholinium ([Ch])-based ILs, at three temperatures (25, 37, and 50 °C). At 25 °C, [Ch]-based IL aqueous solutions enhanced the biocatalytic activity of ASNase, with a maximum increase of the relative ASNase activity (of ca. 250%) achieved by adding cholinium chloride ([Ch]­Cl). Spectroscopic and calorimetric analyses were performed to understand the effect of [Ch]Cl on the ASNase structure, but no significant changes were observed. Although all [Ch]-based ILs enhanced the relative ASNase activity, the positive effects were diminished with increasing the anion alkyl chain length, i.e. from acetate to hexanoate. The increase of temperature to 50 °C caused a negative effect in the catalytic behavior of ASNase, leading, in most cases, to ASNase inactivation. Overall it was evident that [Ch]-based ILs are highly efficient biocatalytic additives to enhance ASNase activity in water (a 2-fold increase by adding less than 0.050 mol·mol–1). This simple and useful approach can be applied to increase the sustainability of several ASNase biocatalytic applications, especially in food processes.

Deep eutectic solvents for the preservation of concentrated proteins: the case of lysozyme in 1 : 2 choline chloride : glycerol

“…This agrees with previous reports on enzymatic activity in DES, as it has been shown that Lyz retains its activity when dissolved or surface-immobilised in DES. 19,42 Similarly, other enzymes were shown to remain functional in other choline-based neoteric solvents, such as L-asparaginase, 43 Lyz, 44 and lactate oxidase, 45 among others.…”

Contemporary Advancement of Cholinium-Based Ionic Liquids for Protein Stability and Long-Term Storage: Past, Present, and Future Outlook

“…The enzymatic activity of HRP, AOC, and azurin was maintained in [Chn]­[DHP] and enhanced thermal stability of FDH was observed in [Chn]­[DHP] . The biocatalytic activity of l -asparaginase, a profitable enzyme for pharmaceutical and food industries, in aqueous solutions of Chn ILs was examined by Pereira and co-workers . It was evident that these ILs are efficient additives to increase the biocatalytic activity of l -asparaginase (up to 2-times) .…”

“…The biocatalytic activity of l -asparaginase, a profitable enzyme for pharmaceutical and food industries, in aqueous solutions of Chn ILs was examined by Pereira and co-workers . It was evident that these ILs are efficient additives to increase the biocatalytic activity of l -asparaginase (up to 2-times) . The effect of a series of Chn ILs on protease acitivity of APA was examined by Ricarte et al .…”

Separation and purification of curcumin using novel aqueous two-phase micellar systems composed of amphiphilic copolymer and cholinium ionic liquids

“…2c) [33]. Like other polymers and ionic compounds [16,33,34], Pluronic F68 and cholinium-based ILs can be thus used as ATPMS-forming components, not only because of ATPMS formation but also for their biocompatible/stabilization characteristics.…”

“…Anyway, these CCM losses are far less intense than those due to pH and temperature increases, confirming the biocompatible character of cholinium ILs. Recently, Magri et al[33] demonstrated that cholinium ILs aqueous solutions maintain the enzymatic activity of Lasparaginase (ASNase). Similarly, [Ch]Cl and [Ch][Ac] have the most structural stabilizing aptitudes, while the increase of IL's anion alkyl chain length and temperature decreased the favorable stabilizing effects…”