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Lerche Bain posted an update 1 week, 3 days ago
Mass spectrometry analysis confirms the high accuracy of incorporation for pAcF at one, two, and five amber sites in sfGFP. The iSAT system updated for ncAA incorporation sets the stage for investigating ribosomal mutations to better understand the fundamental basis of protein synthesis, manufacturing proteins with new properties, and engineering ribosomes for novel polymerization chemistries.Protein-protein interactions are vital to biological processes, but the shape and size of their interfaces make them hard to target using small molecules. Cyclic peptides have shown promise as protein-protein interaction modulators, as they can bind protein surfaces with high affinity and specificity. Dozens of cyclic peptides are already FDA approved, and many more are in various stages of development as immunosuppressants, antibiotics, antivirals, or anticancer drugs. However, most cyclic peptide drugs so far have been natural products or derivatives thereof, with de novo design having proven challenging. A key obstacle is structural characterization cyclic peptides frequently adopt multiple conformations in solution, which are difficult to resolve using techniques like NMR spectroscopy. The lack of solution structural information prevents a thorough understanding of cyclic peptides’ sequence-structure-function relationship. Here we review recent development and application of molecular dynamics simulations with enhanced sampling to studying the solution structures of cyclic peptides. We describe novel computational methods capable of sampling cyclic peptides’ conformational space and provide examples of computational studies that relate peptides’ sequence and structure to biological activity. LY2780301 We demonstrate that molecular dynamics simulations have grown from an explanatory technique to a full-fledged tool for systematic studies at the forefront of cyclic peptide therapeutic design.A new Rh2(II,II) dimer has been synthesized and anchored onto a NiO photocathode. The dirhodium complex acts as both the sensitizer to inject holes into NiO and as catalyst for the production of hydrogen. The single-molecule design circumvents limitations of the conventional multicomponent approach with separate sensitizer and catalyst, thus simplifying the hydrogen production pathway and reducing energy losses associated with additional intermolecular charge transfer steps. The Rh2(II,II) complex absorbs strongly from the ultraviolet throughout the visible range and tails into the near-IR to ∼800 nm, permitting absorption of a significantly greater portion of the solar irradiance as compared to traditional dyes used in dye-sensitized solar cells and photoelectrosynthesis cells. The irradiation of the Rh2-NiO photoelectrode with 655 nm light (53 mW cm-2) results in a photocurrent that reaches 52 μA cm-2 at -0.2 V vs Ag/AgCl in the presence of p-toluenesulfonic acid (0.1 M), with Faradaic efficiencies of H2 production up to 85 ± 5% after 2.5 h without photoelectrode degradation. This work presents the first single-molecule photocatalyst, acting as both the light absorber and catalytic center on NiO, able to generate hydrogen from acidic solutions with red light when anchored to a p-type semiconductor, providing a promising new system for solar fuel production.Passivating defects to suppress recombination is a valid tactic to improve the performance of third-generation perovskite-based solar cells. Pb0 is the primary defect in Pb-based perovskites. Here, tris(pentafluorophenyl)borane is inserted between the perovskite and spiro-OMeTAD layer in SnO2-based planar perovskite solar cells. The incorporation of tris(pentafluorophenyl)borane can effectively passivate Pb0 defects, decreasing recombination at the surface of the perovskite film. Additionally, the modification with tris(pentafluorophenyl)borane decreases the grain boundaries quantity in the perovskite film, enhancing the transportation capability of carriers. The resulting perovskite solar cell gets a high efficiency of 21.42%. While the reference device without tris(pentafluorophenyl)borane treatment acquires an efficiency of 19.07%. More importantly, the stability tests manifest that incorporating tris(pentafluorophenyl)borane in perovskite solar cells is conducive to the stability of the device.There is an urgent need for cheap, stable, and abundant catalyst materials for photoelectrochemical water splitting. Manganese oxide is an interesting candidate as an oxygen evolution reaction (OER) catalyst, but the minimum thickness above which MnOx thin films become OER-active has not yet been established. In this work, ultrathin ( less then 10 nm) manganese oxide films are grown on silicon by atomic layer deposition to study the origin of OER activity under alkaline conditions. We found that MnOx films thinner than 1.5 nm are not OER-active. X-ray photoelectron spectroscopy shows that this is due to electrostatic catalyst-support interactions that prevent the electrochemical oxidation of the manganese ions close to the interface with the support, while in thicker films, MnIII and MnIV oxide layers appear as OER-active catalysts after oxidation and electrochemical treatment. From our investigations, it can be concluded that one MnIII,IV-O monolayer is sufficient to establish oxygen evolution under alkaline conditions. The results of this study provide important new design criteria for ultrathin manganese oxide oxygen evolution catalysts.A green and practical electrochemical method for the synthesis of C-3-sulfonated benzothiophenes from 2-alkynylthioanisoles and sodium sulfinates was developed under oxidant- and catalyst-free conditions. Moderate to good yields of sulfonated benzothiophenes bearing important and useful functional groups have been achieved at a constant current. Preliminary mechanistic studies indicated a tandem radical addition-cyclization pathway. Moreover, the protocol is easy to scale up and exhibits good reaction efficiency.Accurate and sensitive detection of targets in practical biological matrixes such as blood, plasma, serum, or tissue fluid is a frontier issue for most biosensors since the coexistence of both potential reducing agents and protein molecules has the possibility of causing signal interference. Herein, aiming at detection in a complex environment, an advanced and robust peptide-based photocathodic biosensor, which integrated a recognition peptide with an antifouling peptide in one probe electrode, was first proposed. Selecting human chorionic gonadotropin (hCG) as a model target, the recognition peptide with the sequence PPLRINRHILTR was first anchored on the CuBi2O4/Au (CBO/Au) photocathode and then the antifouling peptide with the sequence EKEKEKEPPPPC was further anchored to generate an antifouling biointerface. The peptide-based photocathodic biosensor demonstrated excellent anti-interference to both nonspecific proteins and reducing agents because of the capability of the antifouling peptide. It also exhibited good sensitivity owing to the utilization of the recognition peptide rather than an antibody probe.