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Oliver McDonough posted an update 5 hours, 59 minutes ago
We discovered a highly active GLP-1 analogue in which the native glutamate residue three positions from the N-terminus was replaced with the sulfo-containing amino acid cysteic acid (GLP-1-CYA). The receptor binding and downstream signaling properties elicited by GLP-1-CYA were similar to the wild type GLP-1 peptide. Computational modeling identified a likely mode of interaction of the negatively charged side chain in GLP-1-CYA with an arginine on GLP-1R. This work highlights a strategy of combinatorial peptide screening coupled with chemical exploration that could be used to generate novel agonists for other receptors with peptide ligands.Two graphitic carbon nitride (g-C3N4) molecular building blocks designed for halogen bond driven assembly are evaluated through computational quantum chemistry. Unlike those typically reported in the literature, these g-C3N4-based acceptors each offer three unique sites for halogen bond formation, which when introduced to their donor counterparts, lead to 11, 21, and 31 donor-acceptor complexes. Although halogen bonding interactions are present in all donor-acceptor complexes considered in the work, intermolecular hydrogen bonding emerges in complexes in which an iodine-based donor is directly involved. The halogen bond complexes identified herein feature linear halogen bonds and supportive intermolecular hydrogen bonds that lead to nearly additive electronic binding energies of up to -9.7 (dimers), -18.6 (trimers), and -26.5 kcal mol-1 (tetramers). Select vibrational stretching frequencies (νC-X and νC≡C), and the perturbative shifts they incur upon halogen bond formation, are interrogated and compared to those observed in pyridine- and pyrimidine-based halogen-bonded complexes reported in the literature.Desalination is one of the most effective strategies to solve the problem of freshwater shortage, which is one of the most critical challenges facing global development. Recently, the desalination battery has become an emerging desalination technology thanks to its high salt-removal capacity enabled by the high capacity of battery electrodes and low energy consumption mainly rooted from the high energy recovery during the discharge process. To promote the development of the desalination battery, we must understand the recent advances and the remaining issues in the field. Herein, we comprehensively review the development of the concept and the electrode materials for a desalination battery, summarize the performance of a full desalination battery, and propose perspectives and guidelines.Mouse major urinary protein (MUP) plays a key role in the pheromone communication system. The one-end-closed β-barrel of MUP-I forms a small, deep, and hydrophobic central cavity, which could accommodate structurally diverse ligands. Previous computational studies employed old protein force fields and short simulation times to determine the binding thermodynamics or investigated only a small number of structurally similar ligands, which resulted in sampled regions far from the experimental structure, nonconverged sampling outcomes, and limited understanding of the possible interaction patterns that the cavity could produce. In this work, extensive end-point and alchemical free-energy calculations with advanced protein force fields were performed to determine the binding thermodynamics of a series of MUP-inhibitor systems and investigate the inter- and intramolecular interaction patterns. Three series of inhibitors with a total of 14 ligands were simulated. We independently simulated the MUP-inhibitor complexegand interactions, and 10 residues were found to provide favorable interactions stabilizing the bound state. The two AMBER force fields gave extremely similar interaction networks, and the secondary structures also showed similar behavior. Thus, the intra- and intermolecular interaction networks described with the two AMBER force fields are similar. Therefore, AMBER14SB could still be the default option in free-energy calculations to achieve highly accurate binding thermodynamics and interaction patterns.We present an efficient, linear-scaling implementation for building the (screened) Hartree-Fock exchange (HFX) matrix for periodic systems within the framework of numerical atomic orbital (NAO) basis functions. MK-0859 Our implementation is based on the localized resolution of the identity approximation by which two-electron Coulomb repulsion integrals can be obtained by only computing two-center quantities-a feature that is highly beneficial to NAOs. By exploiting the locality of basis functions and efficient prescreening of the intermediate three- and two-index tensors, one can achieve a linear scaling of the computational cost for building the HFX matrix with respect to the system size. Our implementation is massively parallel, thanks to a MPI/OpenMP hybrid parallelization strategy for distributing the computational load and memory storage. All these factors add together to enable highly efficient hybrid functional calculations for large-scale periodic systems. In this work, we describe the key algorithms and implementation details for the HFX build as implemented in the ABACUS code package. The performance and scalability of our implementation with respect to the system size and the number of CPU cores are demonstrated for selected benchmark systems up to 4096 atoms.Potentiostatic deposition of silicon is performed in sulfolane (SL) and ionic liquid (IL) electrolytes. Electrochemical quartz crystal microbalance with damping monitoring (EQCM-D) is used as main analytical tool for the characterization of the reduction process. The apparent molar mass (Mapp) is applied for in situ estimation of the layer contamination. By means of this approach, appropriate electrolyte composition and substrate type are selected to optimize the structural properties of the layers. The application of SL electrolyte results in silicon deposition with higher efficiency compared to the IL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [BMP][TFSI]. This has been associated with the instability of the IL in the presence of silicon tetrachloride and the enhanced incorporation of IL decomposition products into the growing silicon deposit. X-ray photoelectron spectroscopy (XPS) analysis supports the results about the layer composition, as suggested from the microgravimetric experiments.