FTIR-ATR study for adsorption of trypsin in aqueous environment on bare and TiO2 coated ZnSe surfaces

Guo, Chune; Guo, Xiaojun; Chu, Wubo; Jiang, Nan; Li, He

doi:10.1016/j.cclet.2019.04.067

Cited by 27 publications

(8 citation statements)

References 25 publications

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“…To investigate the secondary structural changes of lipase before and after immobilization, curve-fitting analysis was used to analyze the amide I region located at 1600–1700 cm –1 . , The contents of the secondary structure elements of lipase are shown in Figure . The α-helix content decreased from 21.4 to 19.53% and that of the β-sheet increased from 35.74 to 36.87%.…”

Section: Resultsmentioning

confidence: 99%

Ionic Liquid Modification Optimizes the Interface between Lipase and Magnetic GO for Enhancing Biocatalysis

Liu

et al. 2022

Ind. Eng. Chem. Res.

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In this study, imidazolium-based ionic liquids (ILs) were used to modify carboxymethyl cellulose-coated Fe 3 O 4 nanoparticles with graphene oxide deposition (ILs-MCMC/GO). The prepared composites were characterized and used to immobilize lipase. The prepared biocatalyst (PPL-ILs-MCMC/GO) exhibited higher activity, which was 3.55-fold that of free lipase and 1.41-fold that of immobilized lipase without IL (PPL-MCMC/GO). After reusing 10 times, the residual activity of PPL-ILs-MCMC/GO was 91.3%, which was higher than those of PPL-MCMC/GO (83.6%) and PPL-MCMC (73.6%). In addition, using kinetic analysis, we showed that the affinity between PPL-ILs-MCMC/GO and the substrate was improved. The secondary structures of free and immobilized lipase were analyzed to explain the mechanism by which the performance of PPL-ILs-MCMC/GO was improved. The introduction of imidazole-based IL was useful in improving the microenvironment of immobilized lipase. Furthermore, magnetic supports loaded with lipase could be recovered easily.

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Section: Resultsmentioning

confidence: 99%

Ionic Liquid Modification Optimizes the Interface between Lipase and Magnetic GO for Enhancing Biocatalysis

Liu

et al. 2022

Ind. Eng. Chem. Res.

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“…The guar + SCG + CaCl 2 spectrum is not shown in the figure because it consisted of a bipolar band from which information could not be extracted. Similar cases of a dewatering effect have been reported before on ZnSe ATR windows . As such, this band is possibly an artifact due to the interaction of the ATR window with the gel sample, and therefore, we opted to exclude it.…”

Section: Resultsmentioning

confidence: 99%

“…Similar cases of a dewatering effect have been reported before on ZnSe ATR windows. 47 As such, this band is possibly an artifact due to the interaction of the ATR window with the gel sample, and therefore, we opted to exclude it. In all cases, however, the addition of guar to a salt solution shifts the O−H stretch to lower frequencies, as summarized in Table 3.…”

Section: Resultsmentioning

confidence: 99%

Modulation of the Viscosity of Guar-Based Fracking Fluids Using Salts

et al. 2021

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Fracking is an enhanced oil recovery technology, which uses viscoelastic fluids (fracking fluids) to fracture oil reservoirs and to transport sand within the fractures, to prop them open. This technology enables oil recovery from scarcely permeable formations. Fractured formations release saline water over time. This saline water (called “produced water”) is discarded rather than used to produce fracking fluids because it can decrease fracking fluid viscosity. Nonetheless, it would be advantageous to use produced water to reduce freshwater consumption and wastewater production. Our study analyzes the effect of chloride salts (CaCl2, MgCl2, and Fe(III)Cl) and of sulfate salts (MgSO4 and FeSO4) at different concentrations (0.05–1 M) on the viscosity of aqueous guar solutions. All chloride salts tested increase the viscosity of guar solutions in the concentration range analyzed and promote the formation of small guar aggregates. At 0.05 M concentrations, MgSO4 has effects similar to chloride salts. In contrast, 1 M MgSO4 decreases the viscosity of guar solutions. FeSO4 also decreases the viscosity of aqueous guar solutions, at either 0.05 or 1 M concentrations. The decrease in viscosity of guar solutions is attributed to large guar aggregate formation (as opposed to a cohesive network). Sodium cocoyl glutamate (SCG) increases the viscosity of non-cross-linked guar solutions and the shear viscoelastic moduli of guar solutions cross-linked with sodium tetraborate. Specifically, SCG restores the viscosity of guar solutions with MgSO4 and increases it above values measured in deionized (DI) water in the presence of MgCl2. Attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy shows that hydrogen bonding was more significant in guar + SCG + 0.7 M MgCl2 samples than in guar + SCG + 0.7 M MgSO4, indicating that the formation of a hydrogen-bonded network was correlated to high viscosity. ATR-FTIR also indicates that MgSO4 weakened hydrogen bonding of water clusters, whereas SCG restored it, enabling guar hydration even in the presence of MgSO4. Our study highlights which salts are most problematic (e.g., FeSO4) and proposes a potential additive (SCG) to enhance the viscosity of guar in the presence of selected salts (e.g., magnesium salts) by promoting hydrogen bonding.

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“…These changes in the amide bands indicated that the NH 2 -SNPs interacted with pepsin and changed the pepsin's secondary structure. Guo et al 41 have reported that the amide I band of trypsin had a redshift from 1640 to 1633 cm −1 and the amide II band had a blueshift from 1535 to 1546 cm −1 when trypsin absorbed on an anatase titanium dioxide-coated ZnSe surface, suggesting that an interaction between trypsin and the hydroxyl groups on TiO 2 had occurred. 3.2.6.…”

Section: Fluorescence Emission Spectrummentioning

confidence: 99%

Interactions of Surface-Functionalized Starch Nanoparticles with Pepsin and Trypsin in Simulated Gastrointestinal Fluids

Wang

Sun

Yang

et al. 2020

J. Agric. Food Chem.

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Nanoparticles (NPs) can form a protein corona (PC) with proteins in biological fluids. We examined whether starch nanoparticles (SNPs) form a PC and interact with digestive enzymes in simulated gastric and intestinal fluids. We investigated the adsorption of pepsin and trypsin on unmodified, carboxyl-, and amino-modified SNPs (SNPs, COOH-SNPs, and NH2-SNPs, respectively). Quartz crystal microbalance data showed that a tight and irreversible pepsin corona formed on the NH2-SNPs, pepsin had little or no binding to the SNPs and COOH-SNPs, and trypsin had weak binding to all three kinds of NPs. Dynamic light scattering data showed that pepsin significantly increased the size of the NH2-SNPs from 120 ± 2.6 to 203 ± 12.2 nm and decreased their surface potential from 23.2 ± 1.0 to 12.7 ± 0.2 mV. NH2-SNPs could induce the fluorescence quenching of pepsin and change its secondary structures without affecting its activity.

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FTIR-ATR study for adsorption of trypsin in aqueous environment on bare and TiO2 coated ZnSe surfaces

Cited by 27 publications

References 25 publications

Ionic Liquid Modification Optimizes the Interface between Lipase and Magnetic GO for Enhancing Biocatalysis

Ionic Liquid Modification Optimizes the Interface between Lipase and Magnetic GO for Enhancing Biocatalysis

Modulation of the Viscosity of Guar-Based Fracking Fluids Using Salts

Interactions of Surface-Functionalized Starch Nanoparticles with Pepsin and Trypsin in Simulated Gastrointestinal Fluids

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