How Candida antarctica lipase B can be activated in natural deep eutectic solvents: experimental and molecular dynamics studies

Abstract

BACKGROUND: Natural deep eutectic solvents (NADESs), a class of green solvents which completely accords to 12 principles of green chemistry, have proven to have great potential applications in enzymatic reactions. Despite strong interest, the role of NADESs in these processes, and the molecular interaction between enzymes and NADESs, still remain ambiguous. In the present study, the stability and activity of Candida Antarctica lipase B (CALB) were studied, and the mechanism by which CALB was activated in NADESs was explored systematically from both molecular-and macroscopic-scale perspectives. RESULTS:The results suggested that the activity of CALB in all NADESs was significantly higher than that of the control (ethanol). Moreover, the stability of CALB increased to 115.48 ± 1.36% and 108.54 ± 1.26% in betaine-glycerin (B-Gly) and choline chloride-glycerol (C-Gly), but decreased to 91.69 ± 3.26% and 92.31 ± 3.36% in betaine-xylitol (B-X) and choline chloride-xylitol (C-X), respectively. The results of circular dichroism (CD), fluorescence spectroscopy and molecular dynamics studies (MD) indicated that there was no significant change in the secondary structure of CALB. Furthermore, the results of MD provide some information supporting that CALB was stabilized by the hydrogen(H)-bonding interaction between surface amino residues of CALB and NADESs and was activated via the H-bonding interaction between substrate and NADESs in the acyl-binding pocket. CONCLUSION: The mechanism by which CALB was activated and stabilized via the H-bonding interactions in NADESs wasrevealed in the present study. This provides a scientific basis from which to further explore the potential application of NADESs in enzymatic reactions in food engineering and health-related fields.

Lipase and Metal Chloride Hydrate-Natural Deep Eutectic Solvents Synergistically Catalyze Amidation Reaction via Multiple Noncovalent Bond Interactions

“…As shown in Figure S3 (see the Supporting Information), there was no peak can be found in the range of 0.35 nm around CALB catalytic triad, which indicated that hydrogen-bonding can hardly be formed between CALB catalytic triad and 3c-NADESs. In this context, we can conclude that CALB catalytic triad may not involve in the synergistic effect with 3c-NADESs, which is consist with the results of our previous study in traditional NADESs . Similarly, the large and medium substrate binding pockets were not involved in synergistic effect process (Figure S4A, B, see the Supporting Information).…”

“…However, the mechanism of the synergistic effect between 3c-NADESs and CALB still remains ambiguous. Inspired by previous studies of our group, , we proposed that molecular interactions between 3c-NADESs and CALB/substrates may play a key role in these processes. To further explore it, the molecular interaction between CALB and Mg-CGly3 was investigated by molecular dynamics study (MD).…”

Synthesis of Ibuprofen Monoglyceride in Solventless Medium with Novozym®435: Kinetic Analysis

“…As mentioned previously [20], the esterification of glycerol and ibuprofen drives the free enzyme preparation (Lipozyme CALB L), which proceeds in a biphasic solid-liquid system at temperatures lower than 70 • C and in a biphasic liquid-liquid system at temperatures higher than that value; even at 80 • C, there is no apparent deactivation, and a ibuprofen conversion higher than 90% is achieved in 5 h. This stability can be explained in terms of the preferential hydration of the enzyme and minimal molecular contact with glycerol, thus increasing the enzyme rigidity and its stability [54]. The stabilizing effect of glycerol is even more evident in the formulation and use of deep eutectic solvents (DEPs) based on this polyol for lipase-driven reactions [55]. As regards the effect of the solid support of Novozym ® 435 on the stability of the lipase, Lewatit ® VP OC 1600 resin seems to be amphiphilic, so it adsorbs (and absorbs) hydrophobic components in hydrophilic environments and, on the contrary, hydrophilic compounds-such as glycerol-in hydrophobic environments such as oils in the biodiesel process [23].…”

Effects of Solvents on the Glycerolysis Performance of the SBA-15 Supported Lipases

“…However, while the CALB@SBA-15 was incubated in three solvents at 60 for 8 h, the position of the λ max of was almost fixed Fig. S1B , which indicated that there was no significant change in the secondary structure of CALB 38 . A slight increase in I max over time was observed when RML@SBA-15 incubated in phosphate buffer, and no much difference was observed when it incubated in tert-pentanol and acetonitrile Fig.…”