Attenuation of West Nile Virus NS2B/NS3 Protease by Amino Terminal Copper and Nickel Binding (ATCUN) Peptides

West Nile virus NS2B/NS3 protease (WNVP) is a viable target for the development of antiviral compounds. To that end, catalytic metallopeptides that incorporate the copper-binding ATCUN motif into either the N- or C-terminus of known WNVP targeting peptides have been developed as new families of peptide-based inhibitors. Each metallopeptide was evaluated based on its inhibitory constant (<i>K</i>_I), time-dependent inactivation of the protein, Michaelis–Menten parameters, and the ability to oxidatively modify WNVP. Following catalytic inactivation of WNVP, sequencing by LC-MS/MS demonstrated active site residues Ser135, Thr134, and Thr132, as well as residues in the S2 binding pocket, to be modified by oxidative chemistry. Results from a DNPH-based assay to detect oxidative damage showed the formation of carbonyls in WNVP treated with metallopeptides. These results suggest that the metallopeptides are attenuating WNVP activity by irreversible oxidation of amino acids essential to substrate binding and catalysis

Amino Terminal Copper and Nickel Binding Motif Derivatives of Ovispirin‑3 Display Increased Antimicrobial Activity via Lipid Oxidation

Antimicrobial peptides are short peptides secreted by the innate immune system to protect the host from pathogens. We have investigated the influence of the amino terminal copper and nickel binding (ATCUN) motif on derivatives of ovispirin-3 (OV-3), an α-helical peptide from the cathelicidin family, demonstrating an increased antimicrobial activity toward a broad range of bacteria, relative to OV-3, with MICs as low as 1.3 ± 0.6 μM. Each peptide was able to bind DNA and RNA with micromolar affinity, but did not display nuclease activity in vivo. The ATCUN OV-3 derivatives also displayed an increased membrane leakage and lipid peroxidation relative to Cu-GGH and OV-3 alone. These data suggest that the Cu-ATCUN derivatives inhibit bacteria by binding to the membrane, promoting oxidative damage of the lipids, which then disrupts the bilayer, resulting in cell death. This stands in contrast to the mode of action of OV-3 alone, which permeabilizes the membrane without lipid oxidation

First-Principles Study: Tuning the Redox Behavior of Lithium-Rich Layered Oxides by Chlorine Doping

Lithium-rich layered oxides (LLOs) are promising cathode materials for next-generation lithium ion batteries with high energy density. However, the charge cutoff potential of 4.8 V constrains seriously the actual application of LLOs. Herein, using density functional theory (DFT) calculation, we investigated the tuning mechanism of chlorine doping on the redox potential and redox process in LLOs. The results showed that chlorine doping can decrease the charge potential, modulate the ratio of two redox couples of cation and anion, and lower the band gap of LLOs. These tunings were beneficial for the modification of the safety, cycling stability, and voltage decay of LLOs materials. This work opens up a new route in terms of performance improvement via tuning of redox behavior based on deep understanding of anion doping mechanism

Table_4_Transcriptomic, Proteomic, and Bioelectrochemical Characterization of an Exoelectrogen Geobacter soli Grown With Different Electron Acceptors.xlsx

<p>The ability of Geobacter species to transfer electrons outside cells enables them to play an important role in biogeochemical and bioenergy processes. Our knowledge of the extracellular electron transfer (EET) process in the genus Geobacter is mainly from the study of G. sulfurreducens, and in order to fully investigate the EET mechanisms in the genus Geobacter, other Geobacter species should also be considered. This study focused on the EET of Geobacter soli GSS01, which exhibited a capability of reducing insoluble Fe(III) oxides and generating electrical current comparable with G. sulfurreducens PCA. Electrochemical characterization, including cyclic voltammetry, differential pulse voltammetry, and electrochemical in situ FTIR spectra, revealed that different redox proteins contributed to the electrochemical behaviors of G. soli and G. sulfurreducens. Based on comparative transcriptomic and proteomic analyses, OmcS was the most upregulated protein in both G. soli and G. sulfurreducens cells grown with insoluble Fe(III) oxides vs. soluble electron acceptor. However, the proteins including OmcE and PilA that were previously reported as being important for EET in G. sulfurreducens were downregulated or unchanged in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, and many proteins that were upregulated in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, such as OmcN, are not important for EET in G. sulfurreducens. We also identified 30 differentially expressed small RNAs (sRNAs) in G. soli cells grown with different acceptors. Taken together, these findings help to understand the versatile EET mechanisms that exist in the genus Geobacter and point to the possibility of sRNA in modulating EET gene expression.</p

Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production on CdS/Cu₇S₄/g‑C₃N₄ Ternary Heterostructures

Hydrogen production through photocatalytic water splitting has attracted much attention because of its potential to solve the issues of environmental pollution and energy shortage. In this work, CdS/Cu₇S₄/g-C₃N₄ ternary heterostructures are fabricated by ion exchange between CdS and Cu⁺ and subsequent ultrasonication-assisted self-assembly of CdS/Cu₇S₄ and g-C₃N₄, which provide excellent visible-light photocatalytic activity for hydrogen evolution without any noble metal cocatalyst. With the presence of p–n junction, tuned band gap alignments, and higher charge carrier density in the CdS/Cu₇S₄/g-C₃N₄ ternary heterostructures that can effectively promote the spatial separation and prolong the lifetime of photogenerated electrons, a high hydrogen evolution rate of 3570 μmol g^–1 h^–1, an apparent quantum yield of 4.4% at 420 nm, and remarkable recycling stability are achieved. We believe that the as-synthesized CdS/Cu₇S₄/g-C₃N₄ ternary heterostructures can be promising noble metal-free catalysts for enhanced hydrogen production from photocatalytic water splitting

Table_1_Transcriptomic, Proteomic, and Bioelectrochemical Characterization of an Exoelectrogen Geobacter soli Grown With Different Electron Acceptors.xlsx

<p>The ability of Geobacter species to transfer electrons outside cells enables them to play an important role in biogeochemical and bioenergy processes. Our knowledge of the extracellular electron transfer (EET) process in the genus Geobacter is mainly from the study of G. sulfurreducens, and in order to fully investigate the EET mechanisms in the genus Geobacter, other Geobacter species should also be considered. This study focused on the EET of Geobacter soli GSS01, which exhibited a capability of reducing insoluble Fe(III) oxides and generating electrical current comparable with G. sulfurreducens PCA. Electrochemical characterization, including cyclic voltammetry, differential pulse voltammetry, and electrochemical in situ FTIR spectra, revealed that different redox proteins contributed to the electrochemical behaviors of G. soli and G. sulfurreducens. Based on comparative transcriptomic and proteomic analyses, OmcS was the most upregulated protein in both G. soli and G. sulfurreducens cells grown with insoluble Fe(III) oxides vs. soluble electron acceptor. However, the proteins including OmcE and PilA that were previously reported as being important for EET in G. sulfurreducens were downregulated or unchanged in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, and many proteins that were upregulated in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, such as OmcN, are not important for EET in G. sulfurreducens. We also identified 30 differentially expressed small RNAs (sRNAs) in G. soli cells grown with different acceptors. Taken together, these findings help to understand the versatile EET mechanisms that exist in the genus Geobacter and point to the possibility of sRNA in modulating EET gene expression.</p

Table_3_Transcriptomic, Proteomic, and Bioelectrochemical Characterization of an Exoelectrogen Geobacter soli Grown With Different Electron Acceptors.pdf

<p>The ability of Geobacter species to transfer electrons outside cells enables them to play an important role in biogeochemical and bioenergy processes. Our knowledge of the extracellular electron transfer (EET) process in the genus Geobacter is mainly from the study of G. sulfurreducens, and in order to fully investigate the EET mechanisms in the genus Geobacter, other Geobacter species should also be considered. This study focused on the EET of Geobacter soli GSS01, which exhibited a capability of reducing insoluble Fe(III) oxides and generating electrical current comparable with G. sulfurreducens PCA. Electrochemical characterization, including cyclic voltammetry, differential pulse voltammetry, and electrochemical in situ FTIR spectra, revealed that different redox proteins contributed to the electrochemical behaviors of G. soli and G. sulfurreducens. Based on comparative transcriptomic and proteomic analyses, OmcS was the most upregulated protein in both G. soli and G. sulfurreducens cells grown with insoluble Fe(III) oxides vs. soluble electron acceptor. However, the proteins including OmcE and PilA that were previously reported as being important for EET in G. sulfurreducens were downregulated or unchanged in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, and many proteins that were upregulated in G. soli cells grown with insoluble electron acceptors vs. soluble electron acceptor, such as OmcN, are not important for EET in G. sulfurreducens. We also identified 30 differentially expressed small RNAs (sRNAs) in G. soli cells grown with different acceptors. Taken together, these findings help to understand the versatile EET mechanisms that exist in the genus Geobacter and point to the possibility of sRNA in modulating EET gene expression.</p

High-performance three-dimensional SnO₂-Sb electrode supported on titanium foam substrate prepared by solvothermal process

Three-dimensional (3D) Ti/SnO2–Sb electrode is promising for electrochemical oxidation process (EAOP) application, while hindered by uneven and low catalysts loading, especially on the inner surface of porous substrates. In this study, Ti foam and a solvothermal preparation method were developed for preparing a novel 3D Ti/SnO2–Sb electrode. The catalysts in hollow ellipsoidal shape were well dispersed and stacked on the outer surface, and fully grown along the rugged surface inside Ti foam. Owing to this distinctive structure, the Ti foam/ATO electrode expressed 1.89 times increasing electrochemically active surface area and 48% improved OH· production than the 2D Ti plate/ATO electrode. Moreover, the Ti foam/ATO electrode performed 1.57 years of predicted service life which is 65.8 times than that of Ti plate/ATO electrode. In conclusion, this study provided a facile method and a novel porous substrate to prepare 3D Ti/SnO2–Sb electrode with high performance for EAOP application.</p

Enriched environment improved the behavioral performance in Morris water maze and novel object recognition tests.

<p>(A and B): Enriched environment significantly shortened the escape latencies (F_(1,20) = 10.27, n = 10 and 12 rats per group, P<0.01). and increased the time spent in the target quadrant in the rats with postnatal maternal separation (N = 9–12 per group). (C) Enriched environment significantly increased the time for the rats spent exploring the novel object in the modeled rats (N = 9–11 per group). Note that enriched environment induced increase of the behavioral performance in the Morris water maze test (F_(1,19) = 4.61, n = 9 and 12 rats per group, P<0.05)and novel object recognition test in the control rats. *, P<0.05; **, P<0.01; #, P<0.05; ##, P<0.01.</p

Enriched environment significantly decreased the phosphorylation (serine 421) of MeCP2 (A), and increased the occupancy of MeCP2 in the <i>Crh</i>, but not <i>Gapdh</i>, promoter region (B) in the hippocampal CA1 in the rats with postnatal maternal separation.

<p>N  = 7–8 per group; **, P<0.01.</p