An effective computational-screening strategy for simultaneously improving both catalytic activity and thermostability of α-L-rhamnosidase

Catalytic efficiency and thermostability are the two most important characteristics of enzymes. However, it is always tough to improve both catalytic efficiency and thermostability of enzymes simultaneously. In the present study, a computational strategy with double-screening steps was proposed to simultaneously improve both catalysis efficiency and thermostability of enzymes; and a fungal α-L-rhamnosidase was used to validate the strategy. As the result, by molecular docking and sequence alignment analysis within the binding pocket, seven mutant candidates were predicted with better catalytic efficiency. By energy variety analysis, three among the seven mutant candidates were predict with better thermostability. The expression and characterization results showed the mutant D525N had significant improvements in both enzyme activity and thermostability. Molecular dynamics simulations indicated that the mutations located within the 5 Å range of the catalytic domain, which could improve RMSD, electrostatic, Van der Waal interaction and polar salvation values, and formed water bridge between the substrate and the enzyme. The study indicated that the computational strategy based on the binding energy, conservation degree and mutation energy analyses was effective to develop enzymes with better catalysis and thermostability, providing practical approach for developing industrial enzymes.

Interfacial self-assembly of gold nanoparticle-polymer nanoconjugates into microcapsules with near-infrared light modulated biphasic catalysis efficiency

Gold nanoparticle-based microcapsules based on the interfacial assembly significantly enhanced the biphasic catalytic reaction rate upon near-infrared light irradiation.

ZnO/VNC Material for UV-Photodegradation of Methylene Blue

ZnO materials act as a Photocatalytic reaction and it leads to partial or complete mineralization or decolorization of organic pollutants. Upon irradiation with UV/visible light, semiconductors catalyze undergoes redox reactions in presence of air/O2and water. In the present study Zinc oxide (ZnO) was doped with activated carbon prepared from the stem of the plant material by chemical activation namely,Vitexnegundostemcarbon (VNC). The decolourisation and degradation study of a dye namely, methylene blue (MB) was carried out to find out the efficiency of catalytic property of ZnO/VNC. The reaction was performed at 20, 40, 60 ppm of dye solution with ZnO/VNC material at 10 min interval of time. It found that the prepared ZnO / VNC composite exhibits an enhanced Photocatalytic activity for MB degradation under visible light irradiation and its photo catalysis efficiency was analyzed in specific 663 nm λ max using a UV–vis-spectrophotometer. The surface morphology and functional group present in the ZnO / VNC material was characterized by using FT-IR, SEM and XRD. The result reveals that the ZnO/VNC structure consists of irregular aggregates with rough surfaces and high photodegradation activities of ZnO/VNC on MB solutions are found to be at 20ppm. The ZnO/VNC may be used as an alternative adsorbent to remove MB from aqueous solutions.Keywords: Methylene blue (MB), ZnO / VNC, FT-IR, SEM, XRD

Hydrophilic non-precious metal nitrogen-doped carbon electrocatalysts for enhanced efficiency in oxygen reduction reaction

The role of surface hydrophilicity of non-precious metal N-doped carbon electrocatalysts is found to be positive in enhancing catalysis efficiency for oxygen reduction reaction.

Tuning the wettability of mesoporous silica for enhancing the catalysis efficiency of aqueous reactions

A series of mesoporous silica-based catalysts with finely-tuned surface wettability have been synthesized. Their catalysis efficiency towards aqueous hydrogenations is highly dependent on their surface wettability and can be five times higher than that of the commercial Pd/C catalyst.