DJ-1 is a member of the large and functionally diverse DJ-1/PfpI superfamily and has homologs in nearly all organisms. Because of its connection to parkinsonism and cancer, human DJ-1 has been ...intensely studied for over a decade. The current view is that DJ-1 is a multifunctional oxidative stress response protein that defends cells against reactive oxygen species and mitochondrial damage, although the details of its biochemical function remain unclear. A conserved cysteine residue in DJ-1 (Cys106) is both functionally essential and subject to oxidation to the cysteine-sulfinate and cysteine-sulfonate. Consequently, the oxidative modification of Cys106 has been proposed to allow DJ-1 to act as a sensor of cellular redox homeostasis and to participate in cytoprotective signaling pathways in the cell. This review explores the current evidence for the role of cysteine oxidation in DJ-1 function, with emphasis on emerging models for how oxidative modification may regulate DJ-1's protective function and also contribute to dysfunction and disease.
Mycorrhizal phenotypes arise from interactions among plant and fungal genotypes and the environment. Differences in the stoichiometry and uptake capacity of fungi and plants make arbuscular ...mycorrhizal (AM) fungi inherently more nitrogen (N) limited and less phosphorus (P) limited than their host plants. Mutualistic phenotypes are most likely in P‐limited systems and commensal or parasitic phenotypes in N‐limited systems. Carbon (C) limitation is expected to cause phenotypes to shift from mutualism to commensalism and even parasitism. Two experiments compared the influence of fertilizer and shade on mycorrhizas in Andropogon gerardii across three naturally N‐limited or P‐limited grasslands. A third experiment examined the interactive effects of N and P enrichment and shade on A. gerardii mycorrhizas. Our experiments generated the full spectrum of mycorrhizal phenotypes. These findings support the hypothesis that mutualism is likely in P‐limited systems and commensalism or parasitism is likely in N‐limited systems. Furthermore, shade decreased C‐assimilation and generated less mutualistic mycorrhizal phenotypes with reduced plant and fungal biomass. Soil fertility is a key controller of mycorrhizal costs and benefits and the Law of the Minimum is a useful predictor of mycorrhizal phenotype. In our experimental grasslands arbuscular mycorrhizas can ameliorate P‐limitation but not N‐limitation.
Despite substantial progress in the electrochemical conversion of CO2 into value-added chemicals, the translation of fundamental studies into commercially relevant conditions requires additional ...efforts. Here, we study the catalytic properties of tailored Cu nanocatalysts under commercially relevant current densities in a gas-fed flow cell. We demonstrate that their facet-dependent selectivity is retained in this device configuration with the advantage of further suppressing hydrogen production and increasing the faradaic efficiencies toward the CO2 reduction products compared to a conventional H-cell. The combined catalyst and system effects result in state-of-the art product selectivity at high current densities (in the range 100–300 mA/cm2) and at relatively low applied potential (as low as −0.65 V vs RHE). Cu cubes reach an ethylene selectivity of up to 57% with a corresponding mass activity of 700 mA/mg, and Cu octahedra reach a methane selectivity of up to 51% with a corresponding mass activity of 1.45 A/mg in 1 M KOH.
Electronic tags (both biotelemetry and biologging platforms) have informed conservation and resource management policy and practice by providing vital information on the spatial ecology of animals ...and their environments. However, the extent of the contribution of biological sensors (within electronic tags) that measure an animal's state (e.g., heart rate, body temperature, and details of locomotion and energetics) is less clear. A literature review revealed that, despite a growing number of commercially available state sensor tags and enormous application potential for such devices in animal biology, there are relatively few examples of their application to conservation. Existing applications fell under 4 main themes: quantifying disturbance (e.g., ecotourism, vehicular and aircraft traffic), examining the effects of environmental change (e.g., climate change), understanding the consequences of habitat use and selection, and estimating energy expenditure. We also identified several other ways in which sensor tags could benefit conservation, such as determining the potential efficacy of management interventions. With increasing sensor diversity of commercially available platforms, less invasive attachment techniques, smaller device sizes, and more researchers embracing such technology, we suggest that biological sensor tags be considered a part of the necessary toolbox for conservation. This approach can measure (in real time) the state of free‐ranging animals and thus provide managers with objective, timely, relevant, and accurate data to inform policy and decision making.
Exploitation of glycosylation in enveloped virus pathobiology Watanabe, Yasunori; Bowden, Thomas A.; Wilson, Ian A. ...
Biochimica et biophysica acta. G, General subjects/Biochimica et biophysica acta. General subjects (Online),
10/2019, Letnik:
1863, Številka:
10
Journal Article
Recenzirano
Odprti dostop
Glycosylation is a ubiquitous post-translational modification responsible for a multitude of crucial biological roles. As obligate parasites, viruses exploit host-cell machinery to glycosylate their ...own proteins during replication. Viral envelope proteins from a variety of human pathogens including HIV-1, influenza virus, Lassa virus, SARS, Zika virus, dengue virus, and Ebola virus have evolved to be extensively glycosylated. These host-cell derived glycans facilitate diverse structural and functional roles during the viral life-cycle, ranging from immune evasion by glycan shielding to enhancement of immune cell infection. In this review, we highlight the imperative and auxiliary roles glycans play, and how specific oligosaccharide structures facilitate these functions during viral pathogenesis. We discuss the growing efforts to exploit viral glycobiology in the development of anti-viral vaccines and therapies.
•Enveloped viruses often hijack host-cell glycosylation pathways.•Viral glycans have multifaceted influences on pathobiology.•Glycans have intrinsic functionalities but can also be influenced by immune selection.•Viral glycobiology is emerging as an important parameter during vaccine design.
A laboratory simulation of the thermal hydrolytic pretreatment (THP) process was performed on wastewater sludge, as well as key macromolecular components: proteins, lipids, and polysaccharides. ...Hydrolysis temperatures from 130 to 220
°C were investigated. The objectives of this study were to determine how and over which temperature range THP specifically affects sludge components, and whether hydrolysis temperature can be used to minimize the previously reported drawbacks of THP such as high total ammonia nitrogen (TAN) loads and the production of highly-colored recalcitrant organics. In addition, the applicability of THP to primary sludge (PS) was investigated.
The breakdown of proteins, lipids, and polysaccharides was determined to be temperature dependent, and both waste activated sludge (WAS) and PS responded similarly to THP apart from intrinsic differences in lipid and protein content. Pure carbohydrate solutions were not largely converted to mono- or dimeric reducing sugar units at temperatures below 220
°C, however significant caramelization of starch and production of dextrose and maltose was observed to occur at 220
°C. Volatile fatty acid production during thermal hydrolysis was largely attributed to the breakdown of unsaturated lipids, and long-chain fatty acid production was not significant in terms of previous reports of methanogenic inhibition. Ammonia was produced from protein during thermal hydrolysis, however solids loading rather than thermal hydrolysis temperature appeared to be a more meaningful control for ammonia levels in downstream anaerobic digestion.
In this work, we report a new synthesis method to prepare a Cu nanowire electrocatalyst for selective CO2 reduction at room temperature and atmospheric pressure. Cu nanowire array electrodes were ...prepared through a two-step synthesis of Cu(OH)2 and CuO nanowire arrays on Cu foil substrates and a subsequent electrochemical reduction of the CuO nanowire arrays. The Cu nanowire arrays are able to electrochemically reduce CO2 to CO with a faradaic efficiency of ∼50% at a moderate overpotential of 490 mV, which is significantly higher than that of polycrystalline Cu foil catalysts at identical conditions. The improved faradaic efficiency for the reduction of CO2 to CO is ascribed to the enhanced stabilization for the CO2˙(-) intermediate on the high surface area Cu nanowire arrays.
Summary
Structure determination of the HIV‐1 envelope glycoprotein (Env) presented a number of challenges, but several high‐resolution structures have now become available. In 2013, cryo‐EM and x‐ray ...structures of soluble, cleaved SOSIP Env trimers from the clade A BG505 strain provided the first glimpses into the Env trimer fold as well as more the variable regions. A recent cryo‐EM structure of a native full‐length trimer without any stabilizing mutations had the same core structure, but revealed new insights and features. A more comprehensive and higher resolution understanding of the glycan shield has also emerged, enabling a more complete representation of the Env glycoprotein structure. Complexes of Env trimers with broadly neutralizing antibodies have surprisingly illustrated that most of the Env surface can be targeted in natural infection and that the neutralizing epitopes are almost all composed of both peptide and glycan components. These structures have also provided further evidence of the inherent plasticity of Env and how antibodies can exploit this flexibility by perturbing or even stabilizing the trimer to facilitate neutralization. These breakthroughs have stimulated further design and stabilization of Env trimers as well as other platforms to generate trimers that now span multiple subtypes. These Env trimers when used as immunogens, have led to the first vaccine‐induced neutralizing antibodies for structural and functional analyses.
In this work, the selective electrocatalytic reduction of carbon dioxide to carbon monoxide on oxide‐derived silver electrocatalysts is presented. By a simple synthesis technique, the overall high ...faradaic efficiency for CO production on the oxide‐derived Ag was shifted by more than 400 mV towards a lower overpotential compared to that of untreated Ag. Notably, the Ag resulting from Ag oxide is capable of electrochemically reducing CO2 to CO with approximately 80 % catalytic selectivity at a moderate overpotential of 0.49 V, which is much higher than that (ca. 4 %) of untreated Ag under identical conditions. Electrokinetic studies show that the improved catalytic activity is ascribed to the enhanced stabilization of COOH. intermediate. Furthermore, highly nanostructured Ag is likely able to create a high local pH near the catalyst surface, which may also facilitate the catalytic activity for the reduction of CO2 with suppressed H2 evolution.
Nanostructured surfaces: An oxide‐derived silver electrocatalyst was synthesized for the conversion of carbon dioxide to carbon monoxide with a high Faraday efficiency at low overpotentials. The nanostructure of the catalyst lowered the overpotentials as compared to polycrystalline silver by creating a high local pH value near the surface of the catalyst.
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