Enhancing the Catalytic Performance of Candida antarctica Lipase B by Chemical Modification With Alkylated Betaine Ionic Liquids

Abstract

Various betaine ionic liquids composed of different chain lengths and different anions were designed and synthesized to modify Candida antarctica lipase B (CALB). The results showed that the catalytic activity of all modified lipases improved under different temperature and pH conditions, while also exhibiting enhanced thermostability and tolerance to organic solvents. With an increase in ionic liquid chain length, the modification effect was greater. Overall, CALB modified by [BetaineC16][H2PO4] performed best, with the modified CALB enzyme activity increased 3-fold, thermal stability increased 1.5-fold when stored at 70°C for 30 min, with tolerance increased 2.9-fold in 50% DMSO and 2.3-fold in 30% mercaptoethanol. Fluorescence and circular dichroism (CD) spectroscopic analysis showed that the introduction of an ionic liquid caused changes in the microenvironment surrounding some fluorescent groups and the secondary structure of the CALB enzyme protein. In order to establish the enzyme activity and stability change mechanisms of the modified CALB, the structures of CALB modified with [BetaineC4][Cl] and [BetaineC16][Cl] were constructed, while the reaction mechanisms were studied by molecular dynamics simulations. Results showed that the root mean square deviation (RMSD) and total energy of modified CALB were less than those of native CALB, indicating that modified CALB has a more stable structure. Root mean square fluctuation (RMSF) calculations showed that the rigidity of modified CALB was enhanced. Solvent accessibility area (SASA) calculations exhibited that both the hydrophilicity and hydrophobicity of the modified enzyme-proteins were improved. The increase in radial distribution function (RDF) of water molecules confirmed that the number of water molecules around the active sites also increased. Therefore, modified CALB has enhanced structural stability and higher hydrolytic activity.

The antibacterial activity and mechanism of imidazole chloride ionic liquids on Staphylococcus aureus

“…ILs could be self-assembled into low-dimensional nanoparticles due to their strong interactions between the cations and anions, H-bond direction, and large molecular volume (Dupont, 2011 ; Chen et al, 2014 ). Their unique properties have attracted increasing attention in the biomedical field, such as the extraction and conservation of proteins (Schröder, 2017 ; Veríssimo et al, 2021 ; Xue et al, 2022 ) and nuclear acids (Dinis et al, 2020 ), drug transport enhancers (Md Moshikur et al, 2020 ; Zhang et al, 2020 ), drug carriers (Lu et al, 2020 ; Moshikur et al, 2021 ), drug additives (Tang et al, 2016 ), and disease diagnosis (Zhu et al, 2020 ) and therapy (Albadawi et al, 2021 ; Gao et al, 2021 ). The nanoparticle structure of ILs provides a variety of possibilities for biomedical applications.…”

Ionozymes for Efficient Synthesis of Cadaverine: Offering a Sustainable Way for Bio-nylon 5X Production

“…The preferable microenvironment for enzymatic reactions can affect catalytic properties obviously. − Ionic liquids (ILs), a tunable solvent or cosolvent with favorable biocompatibility, have been proved to have distinct process intensification effects on enzymatic catalysis, − which has been widely applied in lipase-catalyzed transesterification to activate the enzymatic reaction and achieved good catalytic results. − In these ionic microenvironments, ILs could create the local microenvironment around the protein surface and affect the appearance of intermediate production to enhance enzymatic activity and stability. − Currently, the third-generation ILs with low biotoxicity, biocompatibility, and biodegradability have been designed and synthesized for specific enzymatic reactions. − Xue et al designed and synthesized varieties of betaine ILs to modify Candida antarctica lipase B (CALB), and the addition of ILs improved the catalytic activity and the structural stability by 3 times and 1.5 times, respectively. Liu et al explored a bi-enzyme system (aryl alcohol oxidase and lignin peroxidase) to depolymerized lignin in the biocompatible IL system.…”

“…19−21 Currently, the third-generation ILs with low biotoxicity, biocompatibility, and biodegradability have been designed and synthesized for specific enzymatic reactions. 22−26 Xue et al 27 designed and synthesized varieties of betaine ILs to modify Candida antarctica lipase B (CALB), and the addition of ILs improved the catalytic activity and the structural stability by 3 times and 1.5 times, respectively. Liu et al 28 explored a bi-enzyme system (aryl alcohol oxidase and lignin peroxidase) to depolymerized lignin in the biocompatible IL system.…”

Lipase-catalyzed one-pot four-component reaction in water: green construction of substituted 2,3-dihydrothiophenes

“…It is an ideal biocatalyst for numerous applications because of its versatility in catalyzing various reactions, its ability to withstand extreme temperatures, and its compatibility with different solvents. [32][33][34][35][36][37][38][39] In the present study, we focused on the lipase-catalyzed one-pot fourcomponent reaction in water using aldehydes, malonitrile or ethyl cyanoacetate, 2,4-thiazolidinedione, and amines as substrates. As far as we know, the lipase-catalyzed one-pot four-component reaction to synthesize 2,3-dihydrothiophene derivatives in water has not yet been reported (Scheme 1).…”