The Protein Data Bank in Europe (PDBe; pdbe.org) is a partner in the Worldwide PDB organization (wwPDB; wwpdb.org) and as such actively involved in managing the single global archive of biomacromolecular structure data, the PDB. In addition, PDBe develops tools, services and resources to make structure-related data more accessible to the biomedical community. Here we describe recently developed, extended or improved services, including an animated structure-presentation widget (PDBportfolio), a widget to graphically display the coverage of any UniProt sequence in the PDB (UniPDB), chemistry- and taxonomy-based PDB-archive browsers (PDBeXplore), and a tool for interactive visualization of NMR structures, corresponding experimental data as well as validation and analysis results (Vivaldi).
Naturally rare l-erythro (3S,4S)-ketoses were prepared at high temperatures through a simultaneous two-step enzymatic cascade synthesis with excellent stereoselectivity.
Innovations in novel enzyme discoveries impact upon a wide range of industries for which biocatalysis and biotransformations represent a great challenge, i.e., food industry, polymers and chemical industry. Key tools and technologies, such as bioinformatics tools to guide mutant library design, molecular biology tools to create mutants library, microfluidics/microplates, parallel miniscale bioreactors and mass spectrometry technologies to create high-throughput screening methods and experimental design tools for screening and optimization, allow to evolve the discovery, development and implementation of enzymes and whole cells in (bio)processes. These technological innovations are also accompanied by the development and implementation of clean and sustainable integrated processes to meet the growing needs of chemical, pharmaceutical, environmental and biorefinery industries. This review gives an overview of the benefits of high-throughput screening approach from the discovery and engineering of biocatalysts to cell culture for optimizing their production in integrated processes and their extraction/purification.
Hybrid catalysis is an emerging concept that combines chemo- and biocatalysts in a wide variety of approaches. Combining the specifications and advantages of multiple disciplines, it is a very promising way to diversify tomorrow's catalysis.
Direct methanol oxidation is expected to play a central role in low˗polluting future power sources. However, the sluggish and complex electro-oxidation of methanol is one of the limiting factors for any practical application. To solve this issue, the use of plasmonic cathodes is considered a promising way to accelerate the methanol oxidation reaction. In this study we report on a novel approach for achieving enhanced methanol oxidation currents. Perforated gold thin films cathodes were decorated with Pt/Ru via electrochemical deposition and investigated for their ability for plasmon˗enhanced electrocatalytic methanol oxidation in alkaline media. The novel methanol oxidation cathode (AuNHs/PtRu), combing the strong light absorption properties of a gold nanohole array˗based electrode (AuNHs) with surface anchored bimetallic Pt/Ru nanostructures, known for their high activity towards methanol oxidation, proved to be highly efficient in converting methanol via the hot holes generated in the plasmonic electrode. Without light illumination AuNHs/PtRu displayed a maximal current density of 13.7 mA/cm 2 at ˗0.11 V vs. Ag/AgCl. Enhancement to 17.2 mA/cm 2 was achieved under 980 nm laser light illumination at a power density of 2 W/cm 2 . The thermal effect was negligible in this system, underlining a dominant plasmon process. Fast generation and injection of charge carriers were also evidenced by the abrupt change in the current density upon laser irradiation. The good stability of the interface over several cycles makes this system interesting for methanol electro-oxidation.
Hybrid catalysis, which combines chemo‐ and biocatalytic benefits, is an efficient way to address green chemistry principles. 5‐Hydroxymethylfurfural (HMF) is a versatile building block in numerous industrial applications. To date, few studies have described the production of its amine derivatives and their polymers. Finding a good methodology to directly transform HMF to 5‐aminomethyl‐2‐furancarboxylic acid (AMFC) therefore represents an important challenge. After selecting the best oxidation catalyst for HMF conversion to 5‐aldehyde‐2‐furancarboxylic acid and immobilizing a transaminase onto a solid carrier, we implemented the first one‐pot/two‐steps hybrid catalytic process to produce AMFC (77 % yield); this is the most efficient AMFC catalytic production method from HMF reported to date. This process also produced 2,5‐furandicarboxylic acid (21 % yield) as a major secondary product that can be applied to polymer syntheses such as polyethylene furanoate. Herein, we report a novel way to access new biosourced polymers based on HMF oxidized and aminated derivatives.
In the course of a project devoted to the stereoselective synthesis of non-proteinogenic α-amino acids using α-transaminases (α-TA), we report the design and optimization of generic high-throughput continuous assays for the screening of α-TA libraries. These assays are based on the use of L- or D-cysteine sulfinic acid (CSA) as irreversible amino donor and subsequent sulfite titration by colorimetry. The assays' quality was assessed under screening conditions. Hit selection thresholds were accurately determined for every couple of substrates and a library of 232 putative transaminases expressed in Escherichia coli host cells was screened. The reported high throughput screening assays proved very sensitive allowing the detection with high confidence of activities as low as 10 μU (i.e., 0.01 nmol substrate converted per min). The assays were also evidenced to be stereochemically discriminant since L-CSA and D-CSA allowed the exclusive detection of L-TA and D-TA, respectively. These generic assays thus allow testing the stereoselective conversion of a wide range of α-keto acids into α-amino acids of interest. As a proof of principle, the use of 2-oxo-4-phenylbutyric acid as acceptor substrate led to the identification of 54 new α-TA offering an access to valuable L- or D-homophenylalanine.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.