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Fusion proteins play an essential role in the biosciences but suffer from several key limitations, including the requirement for N-to-C terminal ligation, incompatibility of constituent domains, incorrect folding, and loss of biological activity. This perspective focuses on chemical and enzymatic approaches for the post-translational generation of well-defined protein-protein conjugates, which overcome some of the limitations faced by traditional fusion techniques. Methods discussed range from chemical modification of nucleophilic canonical amino acid residues to incorporation of unnatural amino acid residues and a range of enzymatic methods, including sortase-mediated ligation. Through summarizing the progress in this rapidly growing field, the key successes and challenges associated with using chemical and enzymatic approaches are highlighted and areas requiring further development are discussed.

Mass-spectrometry (MS)-based proteomics is a powerful and robust platform for studying the interactions between biological systems during health and disease. Bacterial infections represent a significant threat to global health and drive the pursuit of novel therapeutic strategies to combat emerging and resistant pathogens. During infection, the interplay between a host and pathogen determines the ability of the microbe to survive in a hostile environment and promotes an immune response by the host as a protective measure. It is the protein-level changes from either biological system that define the outcome of infection, and MS-based proteomics provides a rapid and effective platform to identify such changes. In particular, proteomics detects alterations in protein abundance, quantifies protein secretion and (or) release, measures an array of post-translational modifications that influence signaling cascades, and profiles protein–protein interactions through protein complex and (or) network formation. Such information provides new insight into the role of known and novel bacterial effectors, as well as the outcome of host cell activation. In this Review, we highlight the diverse applications of MS-based proteomics in profiling the relationship between bacterial pathogens and the host. Our work identifies a plethora of strategies for exploring mechanisms of infection from dual perspectives (i.e., host and pathogen), and we suggest opportunities to extrapolate the current knowledgebase to other biological systems for applications in therapeutic discovery.

Cambarus veteranus and Cambarus callainus are highly imperiled crayfish that are federally listed. These crayfish are native to the coalfields region of central Appalachia. The dominant industry and land use in this region is coal mining. The most common method of mining in this area, surface mining, employs large ponds to hold a slurry water byproduct created when cleaning the coal. Intermittently, the containment structures for these ponds fail causing the uncontrolled release of coal slurry. There is a lack of data on the rates of bioaccumulation of elements commonly associated with mining in crayfish within this region before and after these spills occur, such that there is no reference to know what concentrations constitutes “normal” rates. Chemical pollutants along with increased sedimentation from industrial sources are known to cause adverse effects in crustaceans and can be lethal. Therefore, it is crucial to better understand what baseline conditions of bioaccumulation are within this region before spills occur. This study assessed the bioaccumulation of magnesium (Mg), aluminum (Al), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), and lead (Pb) in non-imperiled crayfish by analyzing hepatopancreas and gill tissues. We analyzed rates of bioaccumulation grouped by crayfish genus and tissue type throughout each season Differences between genus and tissue type, reference and degraded sites, and between crayfish tissue type, periphyton, and water were also investigated. Seasonal variation in the concentrations of elements in crayfish tissue was found with higher element concentrations during winter and lower concentrations during summer. Differences between crayfish tissue type, periphyton, and water were also found, with periphyton typically having the highest concentrations, water having the lowest concentrations, and crayfish tissue being between concentrations found in water and periphyton.

Purpose Wire + arc additive manufacturing (WAAM) uses existing welding technology to make a part from metal deposited in an almost net shape. WAAM is flexible in that it can use multiple materials successively or simultaneously during the manufacturing of a single component. Design/methodology/approach In this work, a gas metal arc welding (GMAW) based wire + arc additive manufacturing (WAAM) system has been developed to use two material successively and fabricate bimetallic additively manufactured structure (BAMS) of low carbon steel and AISI 316L stainless steel (SS). Findings The interface shows two distinctive zones of LCS and SS deposits without any weld defects. The hardness profile shows a sudden increase of hardness at the interface, which is attributed to the migration of chromium from the SS. The tensile test results show that the bimetallic specimens failed at the LCS side, as LCS has lower strength of the materials used. Originality/value The microstructural features and mechanical properties are studied in-depth with special emphasis on the bimetallic interface.

International audience; The interactions between a permanent magnet (PM) and a coated conductor tape lies at the heart of several types of high-temperature superconducting (HTS) devices, including the HTS dynamo. The applied magnetic field from a PM is typically highly spatially inhomogeneous with large field gradients occurring near the edges of the PM. This situation differs substantially from the well known Brandt analytical model, which describes flux penetration and current behaviour of type-II supercon- ducting strips in a spatially-homogeneous applied magnetic field. The Brandt model also assumes the superconductor exhibits a constant critical current (Jc) throughout, and hence does not take into account the more complex behaviour of practical HTS tapes which exhibit an angular magnetic field-dependence of the critical current, Jc(B,θ). In this work, a finite-element model is developed to include such considerations and describe the interaction between a permanent magnet and an HTS coated-conductor wire at small flux gap distances similar to those used in the HTS dynamo. The effect of varying key parameters is studied including: (1) changing the critical current, (2) including an anisotropic magnetic field dependence to the critical current density, (3) changing the relative width of the PM to the coated conductor tape, and (4) changing the flux gap between the magnet and the HTS tape. The effects on the flux penetration and current behaviour of the HTS tape are calculated and compared to the Brandt model. Of particular interest are the key differences in the flux penetration profile which are observed when the magnet width is much smaller than the width of the coated conductor tape.

Cambarus veteranus and Cambarus callainus are federally endangered and threatened crayfish, that live in the coalfields region of central Appalachia. The dominant industry and land use in this region is coal mining. Currently, the most common form of coal mining in this region is surface mining, also known as mountaintop removal mining. There is a lack of data on the specific impacts of pollutants from mining on crayfish and their congeners. Chemical pollutants along with increased sedimentation from industrial sources are known to cause adverse effects in crustaceans and can even be lethal. It is crucial to better understand how these pollutants are affecting crayfishes inhabiting coalfield streams. This study will assess the bioaccumulation of the metals arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and selenium (Se) in non-imperiled cambarid crayfish that are being used as surrogate species for C. veteranus and C. callainus by analyzing the hepatopancreas and gill tissues. Physical maladies, such as deformed dactyl and gill melanization, will also be quantified. This data, as well as species abundance at each site, will be analyzed to better understand the effects of mining on crayfish.

Primary burrowing crayfish life history and ecology is largely due to their cryptic habitat preferences. Cambarus monongalensis, arguably the most charismatic of all crayfishes, lacks basic life history and habitat data because of the aforementioned obstacles. This study seeks to determine the life history and ecological preferences of populations of C. monongalensis in the northern panhandle of West Virginia and Southwestern Pennsylvania with notes on its natural history. Life history data will include form change and reproductive patterns including juvenile size of departure from the maternal burrow. Habitat data were collected using external burrow morphology and burrow locations within a standardized area collected seasonally to determine the preferences and cyclical patterns of crayfishes. With these data, the conservation of this species, and others that follow a similar life history strategy, is possible

Post-translational modifications of proteins are ubiquitous in living organisms, as they enable an accurate control of the interactions of these macromolecules. For mechanistic studies, it would be highly advantageous to be able to produce in vitro post-translationally modified proteins with site-specificity. Here, we demonstrate one facile way to achieve this goal through the use of post-translational chemical mutagenesis. We illustrate this approach by performing site-specific phosphorylation and methylation of tau, a protein that stabilizes microtubules and whose aggregation is closely linked with Alzheimer's disease. We then verify the effects of the post-translational modifications on the ability of tau to control microtubule polymerization, revealing in particular an unexpected role for phosphorylation at S199, which is outside the microtubule-binding region of tau. These results show how the chemical mutagenesis approach that we present enables the systematic analysis of site-specific post-translational modifications of a key protein involved in the pathogenesis of Alzheimer's disease.