Gravesenfogh9290

Enzymes are dynamical macromolecules and their conformation can be altered via local fluctuations of side chains, large scale loop and even domain motions which are intimately linked to their function. Herein, we have addressed the role of dynamic flexibility in the catalytic activity of a thermostable enzyme almond beta-glucosidase (BGL). Optical spectroscopy and classical molecular dynamics (MD) simulation were employed to study the thermal stability, catalytic activity and dynamical flexibility of the enzyme. An enzyme assay reveals high thermal stability and optimum catalytic activity at 333 K. Polarization-gated fluorescence anisotropy measurements employing 8-anilino-1-napthelenesulfonic acid (ANS) have indicated increasing flexibility of the enzyme with an increase in temperature. A study of the atomic 3D structure of the enzyme shows the presence of four loop regions (LRs) strategically placed over the catalytic barrel as a lid. MD simulations have indicated that the flexibility of BGL increases concurrently with temperature through different fluctuating characteristics of the enzyme's LRs. Principal Component Analysis (PCA) and the Steered Molecular Dynamics (SMD) simulation manifest the gatekeeper role of the four LRs through their dynamic fluctuations surrounding the active site which controls the catalytic activity of BGL.A synergistic effect between dimethylglyoxime (to stabilize the Ti-O ribbon) and nonlinear dicarboxylate ligands (to bend the Ti-O ribbon) has been developed to form a series of planar chiral titanium-oxo clusters with high solution stability. The charality of the obtained clusters has been studied by X-ray structural and CD spectroscopy analysis.In this study, oligo-prolines, (Pro)n (n = 6 and 9) inspired by the backbone structure of collagen, were evaluated as a novel non-ionic anti-fouling peptide. Two oligo-prolines with a cysteine residue were synthesized and immobilized on gold substrates via Au-thiol binding. The surfaces immobilized with oligo-prolines, and forming a polyproline-II conformation, indicated hydrophilic properties (water contact angle ≈ 25 degrees). The degree of adsorption of human serum albumin, human fibrinogen, and bovine serum components on these surfaces was quantified using a quartz crystal. The immobilization of oligo-prolines prevented the adsorption of proteins and serum components including small molecules, such as fatty acids. Pro9 specifically indicated good resistance to the adsorption of all components due to the highly-packed Pro9 chains on the surface. The adhesion of fibroblasts was drastically suppressed on the surfaces immobilized with oligo-prolines. Our findings suggest that oligo-proline-immobilized surfaces, specifically Pro9-s, are useful for the development of novel vascular devices that have ultra-low fouling properties.The influence of an external electric field (EEF) on the deprotonation reaction of Fe3+-solvated molecules was studied using reactive molecular dynamics (ReaxFF MD) simulations. BMS-387032 solubility dmso It was examined in terms of changes in structural properties, kinetics, system energy, and reaction products under an EEF, and the results were further verified experimentally. The research results show that the presence of an EEF will affect the distribution of water molecules around Fe3+ and provide energy for the fracturing of O-H bonds. The increase in the state of reaction products represented by H+ also suggests that the EEF can promote the deprotonation reaction of Fe3+-solvated molecules. The viscosity of the system is significantly increased under an EEF. The experimental results for verification show that the pH of the FeCl3 solution is reduced under the action of an EEF, which means that the hydrolysis of Fe3+ has been promoted. The experimental results are consistent with the results of the MD simulations.Photonic crystals (PCs) are periodic dielectric structures with photonic bandgaps and they can be used to control and manipulate photons effectively. Novel photonic crystal materials with tunable bandgaps can be prepared by changing the refractive index of the dielectric or lattice parameters under external stimuli, while using temperature to adjust the photonic band gap is a simple and convenient method. In this paper, silica PCs having different pseudo-gaps in the range of 450-750 nm were prepared with colloidal SiO2 spheres of different sizes. Thermo-sensitive PNIPAM hydrogel was then infiltrated into the PCs to obtain PNIPAM-PCs, whose pseudo-gap blue-shifted when the temperature was changed from 24 to 34 °C and exhibited good reversibility. The PCs with tunable bandgaps are significant for the development of integrated photonic devices, sensors, and in detection and other technologies.Electrocatalytic reduction is considered to be a promising way for the green and sustainable conversion of CO2 into fuels and chemicals. Transition metals, copper particularly, are the most popular catalysts for this process and a wide range of reduced carbon compounds can be obtained. In previous studies, the binding energies of *CO and *OH were adopted as descriptors to screen out the best catalyst. However, this approach is not effective for those catalysts that have a weak interaction with CO molecules. Herein, we present a theoretical work by using the d-band centre as a descriptor to predict the best catalyst for CO2 reduction to CH4 based on newly synthesized metal organic frameworks, namely porous M3 (HITP)2 (HITP, 2,3,6,7,10,11-hexaiminotriphenylene) two-dimensional metal organic frameworks (MN4-MOFs). The limiting potentials of MN4-MOFs (M = Ti to Cu) for CO2 reduction, determined by the formation energy of *OCHOH and *OCH2OH species, are closely correlated with the d-band centre from the TiN4-MOF to CuN4-MOF. Among the eight catalysts examined, the FeN4-MOF turns out to be the most active one for the selective conversion of CO2 to CH4 with an ultralow limiting potential of only -0.41 V, which is comparable or even lower than that of other reported CO2 reduction catalysts.Improving the efficiency of triplet fusion upconversion (TF-UC) in the solid-state is still challenging due to the aggregation and phase separation of chromophores. In this work, two 9,10-diphenylanthracene (DPA) derivatives based on the modification of the 9,10-phenyl rings with bulky isopropyl groups (bDPA-1 and bDPA-2) were used as emitters. By using platinum octaethylporphyrin (PtOEP) as the sensitizer, TF-UC performance was comprehensively investigated in 3 media toluene solution, polyurethane thin film and nano/micro-crystals in a polyvinyl alcohol matrix. Only a small difference in upconversion efficiency between the bulky DPAs and the DPA reference was observed in toluene solution and polyurethane thin film. However, a large improvement of TF-UC quantum yield was achieved in bDPA-2/PtOEP crystals (ΦUC = (0.92 ± 0.05)%) with a low excitation intensity threshold (52 mW cm-2) compared to that of DPA/PtOEP crystals (ΦUC = (0.09 ± 0.03)%). This difference was largely attributed to improved dispersibility of the PtOEP sensitizer in the bDPA-2 emitter crystals.