Enzymes employ a wide range of protein motions to achieve efficient catalysis of chemical reactions. While the role of collective protein motions in substrate binding, product release, and regulation of enzymatic activity is generally understood, their roles in catalytic steps per se remain uncertain. Here, molecular dynamics simulations, enzyme kinetics, X-ray crystallography, and nuclear magnetic resonance spectroscopy are combined to elucidate the catalytic mechanism of adenylate kinase and to delineate the roles of catalytic residues in catalysis and the conformational change in the enzyme. This study reveals that the motions in the active site, which occur on a time scale of picoseconds to nanoseconds, link the catalytic reaction to the slow conformational dynamics of the enzyme by modulating the free energy landscapes of subdomain motions. In particular, substantial conformational rearrangement occurs in the active site following the catalytic reaction. This rearrangement not only affects the reaction barrier but also promotes a more open conformation of the enzyme after the reaction, which then results in an accelerated opening of the enzyme compared to that of the reactant state. The results illustrate a linkage between enzymatic catalysis and collective protein motions, whereby the disparate time scales between the two processes are bridged by a cascade of intermediate-scale motion of catalytic residues modulating the free energy landscapes of the catalytic and conformational change processes.In this work, we employed broad-band dielectric spectroscopy to determine the solubility limits of nimesulide in the Kollidon VA64 matrix at ambient and elevated pressure conditions. Our studies confirmed that the solubility of the drug in the polymer matrix decreases with increasing pressure, and molecular dynamics controls the process of recrystallization of the excess of amorphous nimesulide from the supersaturated drug-polymer solution. More precisely, recrystallization initiated at a certain structural relaxation time of the sample stops when a molecular mobility different from the initial one is reached, regardless of the temperature and pressure conditions. https://www.selleckchem.com/ Finally, based on the presented results, one can conclude that by transposing vertically the results obtained at elevated pressures, one can obtain the solubility limit values corresponding to low temperatures. This approach was validated by the comparison of the experimentally determined points with the theoretically obtained values based on the Flory-Huggins theory.Studies on multiemission fluorescent carbon dots (CDs) excited at one wavelength are extremely promising because of their label-free property, facile synthesis, multicolor visualization, and prevention of background interference. In this study, a novel template strategy to develop multiemission carbon dots (M-CDs) using fluorescent precursors has emerged. We attempted to elucidate the relationship between precursor substances and luminescence origins. The M-CDs prepared by calcein demonstrate three emissions, ultraviolet (UV), blue, and green, which are attributed to the solvent, surface defect, and precursor aromatic ring luminophores, respectively. Also, through a regular adjustment of the amount of NaOH or the solvothermal synthesis time, the expected optical requirements were successfully met by the M-CDs, which is a better capability than that of previously reported M-CDs. In addition, a multicolor sensor designed with M-CDs and rhodamine B (RhB) has been successfully applied in cell imaging. When exposed to different pH media, the fluorescence (FL) emission shows a linear relationship with the pH value, displaying a profuse color evolution from dark blue to light blue, cyan, green, yellow, and finally, orange.Electronic tattoos as an emerging epidermal electronic are alluring in the field of wearable electronics for their lightweight and noninvasive properties. However, the combination of flexibility, skin biocompatibility, adhesion, repairability, and erasability remains a challenge for fabricating electronic tattoos. Hence, a dynamic ionic liquid is prepared which is ideally suited for making an electronic tattoo with these challenging features at the same time. Such an intrinsically flexible electronic tattoo can be firmly attached to human skin with negligible irritation. More importantly, the existence of dynamic covalent chemistry provides the electronic tattoo with healing and erasable abilities under mild redox conditions. Owing to the high ionic conductivity of ionic liquids, the electronic tattoo exhibits excellent sensing performance in response to the temperature variation and tensile strain, which can intelligently monitor body temperature, pulse, and movement. As an extension of the application, a specially designed quadrilateral electronic tattoo can sense and distinguish multiple signals simultaneously. This concept of electronic tattoo based on the dynamic ionic liquid shows great potentials in the applications of intelligent wearable electronics.The crystalline porous organic framework offers a highly ordered and stable structure under hydrated conditions at high temperatures. Here, we demonstrated a method for preparing high-performance membrane buildup using "heterogeneous networks" and "polymer phase-separated nanochannels". A well-interconnected "nanochannel" with a "crystalline organic framework" forms a highly stable hybrid membrane above 80 °C under 100% hydration under acidic and basic conditions. The prepared structure provides a self-standing membrane that easily overcomes the problem faced by conventional high ion-exchange capacity (IEC)-based membranes such as swelling, gelling, fragility, and dissolving at elevated temperatures. Apart from structural stability, it also shows better chemical stability with enhanced proton conduction at elevated temperatures. This proton conduction with better structural stability in the high IEC sample confirms from thermal analysis, whereas it also offers relatively low in-plane membrane swelling as compared to the conventional membranes. These hybrid membranes were further combined with the FAA-3 membrane to manufacture a reverse electrodialysis system for generating a power output. We also evaluated the maximum power density (Pmax) of the stack theoretically and experimentally. The determined net power density (Pnet) is reported to be 0.45 W m-2 at a flow rate of 40 mL min-1. These results confirm that the developed membrane can withstand robustly under realistic ambient conditions maintaining stable cell performance.