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Antimetabolites. --- Hydroxylation. --- Antimetabolites --- Drugs --- Hydroxylation --- Antimétabolites --- Médicaments --- Hydroxylation --- Metabolism --- Métabolisme
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Amines --- Hydroxylation --- Industrial accidents --- Accidents --- Investigation
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Post-translational modifications (PTMs) are widely employed by all living organisms to control the enzymatic activity, localization or stability of proteins on a much shorter time scale than the transcriptional control. In eukarya, global analyses consistently reveal that proteins are very extensively phosphorylated, acetylated and ubiquitylated. Glycosylation and methylation are also very common, and myriad other PTMs, most with a proven regulatory potential, are being discovered continuously. The emergent picture is that PTM sites on a single protein are not independent; modification of one residue often affects (positively or negatively) modification of other sites on the same protein. The best example of this complex behavior is the histone “bar-code” with very extensive cross-talk between phosphorylation, acetylation and methylation sites. Traditionally it was believed that large networks of PTMs exist only in complex eukaryal cells, which exploit them for coordination and fine-tuning of various cellular functions. PTMs have also been detected in bacteria, but the early examples focused on a few important regulatory events, based mainly on protein phosphorylation. The global importance (and abundance) of PTMs in bacterial physiology was systematically underestimated. In recent years, global studies have reported large datasets of phosphorylated, acetylated and glycosylated proteins in bacteria. Other modifications of bacterial proteins have been recently described: pupylation, methylation, sirtuin acetylation, lipidation, carboxylation and bacillithiolation. As the landscape of PTMs in bacterial cells is rapidly expanding, primarily due to advances of detection methods in mass spectrometry, our research field is adapting to comprehend the potential impact of these modifications on the cellular physiology. The field of protein phosphorylation, especially of the Ser/Thr/Tyr type, has been profoundly transformed. We have become aware that bacterial kinases phosphorylate many protein substrates and thus constitute regulatory nodes with potential for signal integration. They also engage in cross-talk and eukaryal-like mutual activation cascades. The regulatory potential of protein acetylation and glycosylation in bacteria is also rapidly emerging, and the cross-talk between acetylation and phosphorylation has been documented. This topic deals with the complexity of the PTM landscape in bacteria, and focus in particular on the physiological roles that PTMs play and methods to study them. The topic is associated to the 1st International Conference on Post-Translational Modifications in Bacteria (September 9-10, 2014, Göttingen, Germany).
Infection --- Phosphorylation --- Hydroxylation --- Protein Kinases --- S-thiolation --- Proteomics --- Bacteria --- Dehydration --- N-glycosylation --- antimicrobial peptides --- Infection --- Phosphorylation --- Hydroxylation --- Protein Kinases --- S-thiolation --- Proteomics --- Bacteria --- Dehydration --- N-glycosylation --- antimicrobial peptides
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Post-translational modifications (PTMs) are widely employed by all living organisms to control the enzymatic activity, localization or stability of proteins on a much shorter time scale than the transcriptional control. In eukarya, global analyses consistently reveal that proteins are very extensively phosphorylated, acetylated and ubiquitylated. Glycosylation and methylation are also very common, and myriad other PTMs, most with a proven regulatory potential, are being discovered continuously. The emergent picture is that PTM sites on a single protein are not independent; modification of one residue often affects (positively or negatively) modification of other sites on the same protein. The best example of this complex behavior is the histone “bar-code” with very extensive cross-talk between phosphorylation, acetylation and methylation sites. Traditionally it was believed that large networks of PTMs exist only in complex eukaryal cells, which exploit them for coordination and fine-tuning of various cellular functions. PTMs have also been detected in bacteria, but the early examples focused on a few important regulatory events, based mainly on protein phosphorylation. The global importance (and abundance) of PTMs in bacterial physiology was systematically underestimated. In recent years, global studies have reported large datasets of phosphorylated, acetylated and glycosylated proteins in bacteria. Other modifications of bacterial proteins have been recently described: pupylation, methylation, sirtuin acetylation, lipidation, carboxylation and bacillithiolation. As the landscape of PTMs in bacterial cells is rapidly expanding, primarily due to advances of detection methods in mass spectrometry, our research field is adapting to comprehend the potential impact of these modifications on the cellular physiology. The field of protein phosphorylation, especially of the Ser/Thr/Tyr type, has been profoundly transformed. We have become aware that bacterial kinases phosphorylate many protein substrates and thus constitute regulatory nodes with potential for signal integration. They also engage in cross-talk and eukaryal-like mutual activation cascades. The regulatory potential of protein acetylation and glycosylation in bacteria is also rapidly emerging, and the cross-talk between acetylation and phosphorylation has been documented. This topic deals with the complexity of the PTM landscape in bacteria, and focus in particular on the physiological roles that PTMs play and methods to study them. The topic is associated to the 1st International Conference on Post-Translational Modifications in Bacteria (September 9-10, 2014, Göttingen, Germany).
Infection --- Phosphorylation --- Hydroxylation --- Protein Kinases --- S-thiolation --- Proteomics --- Bacteria --- Dehydration --- N-glycosylation --- antimicrobial peptides
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Post-translational modifications (PTMs) are widely employed by all living organisms to control the enzymatic activity, localization or stability of proteins on a much shorter time scale than the transcriptional control. In eukarya, global analyses consistently reveal that proteins are very extensively phosphorylated, acetylated and ubiquitylated. Glycosylation and methylation are also very common, and myriad other PTMs, most with a proven regulatory potential, are being discovered continuously. The emergent picture is that PTM sites on a single protein are not independent; modification of one residue often affects (positively or negatively) modification of other sites on the same protein. The best example of this complex behavior is the histone “bar-code” with very extensive cross-talk between phosphorylation, acetylation and methylation sites. Traditionally it was believed that large networks of PTMs exist only in complex eukaryal cells, which exploit them for coordination and fine-tuning of various cellular functions. PTMs have also been detected in bacteria, but the early examples focused on a few important regulatory events, based mainly on protein phosphorylation. The global importance (and abundance) of PTMs in bacterial physiology was systematically underestimated. In recent years, global studies have reported large datasets of phosphorylated, acetylated and glycosylated proteins in bacteria. Other modifications of bacterial proteins have been recently described: pupylation, methylation, sirtuin acetylation, lipidation, carboxylation and bacillithiolation. As the landscape of PTMs in bacterial cells is rapidly expanding, primarily due to advances of detection methods in mass spectrometry, our research field is adapting to comprehend the potential impact of these modifications on the cellular physiology. The field of protein phosphorylation, especially of the Ser/Thr/Tyr type, has been profoundly transformed. We have become aware that bacterial kinases phosphorylate many protein substrates and thus constitute regulatory nodes with potential for signal integration. They also engage in cross-talk and eukaryal-like mutual activation cascades. The regulatory potential of protein acetylation and glycosylation in bacteria is also rapidly emerging, and the cross-talk between acetylation and phosphorylation has been documented. This topic deals with the complexity of the PTM landscape in bacteria, and focus in particular on the physiological roles that PTMs play and methods to study them. The topic is associated to the 1st International Conference on Post-Translational Modifications in Bacteria (September 9-10, 2014, Göttingen, Germany).
Infection --- Phosphorylation --- Hydroxylation --- Protein Kinases --- S-thiolation --- Proteomics --- Bacteria --- Dehydration --- N-glycosylation --- antimicrobial peptides
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α-hydroxyketone derivatives are organic scaffolds widely encountered in natural or pharmaceutical active compounds. Many synthetic routes were reported in the literature but within the actual context of developing greener chemical processes, strategies involving transition-metal free synthesis using widely available molecular oxygen as the oxidizing source will be considered. Procedures for the hydroxylation of ketones with molecular oxygen have been already reported in batch but left with quite unresolved safety issues. This work aimed at developing a continuous-flow system allowing the safe hydroxylation of ketone-substrates using the intrinsic properties of flow chemistry. Herein, we report a green and safe continuous flow procedure towards the synthesis of α-hydroxylated ketones. Conditions were first developed on a model substrate, namely, isobutyrophenone. The reaction conditions involved FDA class 3 and Chem21 green solvents, including ethanol and DMSO, as well as reactants presenting a low toxicity profile. Once all parameters were optimized, the conditions were applied to a small library of substrates to assess its efficiency. Enolizable ketones or esters were selected as potential substrates. Our procedure was then used for the synthesis of an important α-hydroxylated ketone intermediate for the preparation of active pharmaceutical ingredient ketamine. This synthesis worked efficiently under our conditions since total conversion and selectivity was achieved. The reaction conditions were next transposed to a larger mesofluidic pilot scale reactor, thus enabling the preparation of 1.3 kg per day with high conversions and selectivity.
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In this thesis, Xiaoshi Wang investigates the function and mechanism of a newly discovered heme-thiolate peroxygenase, AaeAPO. This enzyme class comes from Agrocybe aegerita and is used in the conversion of inert hydrocarbons to alcohols. Xiaoshi's work focuses on an extracellular P450 enzyme which is not limited in its stability and lack of solubility and therefore is relevant for widespread industrial use. The author demonstrates that the peroxygenase catalyzes a wide range of reactions. In some cases the author even describes very difficult transformations in molecules that are highly inert. Her detailed investigations provide a mechanistic framework for how the peroxygenase catalyzes such a large number of reactions. A major highlight of this thesis is the identification of key short-lived intermediates in the catalytic cycle of the peroxygenase, using rapid kinetic and spectroscopic methods, as well as the elucidation of the thermodynamic properties of these high-energy intermediates. This work adds new insight into an important class of enzymes.
Biochemistry --- Chemistry --- Physical Sciences & Mathematics --- Heme oxygenase. --- Hydroxylation. --- Alkanes. --- Paraffins --- Hydrocarbons --- Chemical reactions --- Oxygenases --- Chemistry, Organic. --- Enzymes. --- Catalysis. --- Organic Chemistry. --- Enzymology. --- Activation (Chemistry) --- Chemistry, Physical and theoretical --- Surface chemistry --- Biocatalysts --- Ferments --- Soluble ferments --- Catalysts --- Proteins --- Enzymology --- Organic chemistry --- Haem oxygenase --- Iron enzymes --- Organic chemistry. --- Enzymes
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In the last decade there have been numerous advances in the area of rhodium-catalyzed hydroformylation, such as highly selective catalysts of industrial importance, new insights into mechanisms of the reaction, very selective asymmetric catalysts, in situ characterization and application to organic synthesis. The views on hydroformylation which still prevail in the current textbooks have become obsolete in several respects. Therefore, it was felt timely to collect these advances in a book. The book contains a series of chapters discussing several rhodium systems arranged according to ligand type, including asymmetric ligands, a chapter on applications in organic chemistry, a chapter on modern processes and separations, and a chapter on catalyst preparation and laboratory techniques. This book concentrates on highlights, rather than a concise review mentioning all articles in just one line. The book aims at an audience of advanced students, experts in the field, and scientists from related fields. The didactic approach also makes it useful as a guide for an advanced course.
Hydroformylation. --- Rhodium catalysts. --- Chemistry, inorganic. --- Chemistry, Physical organic. --- Chemical engineering. --- Chemistry, Organic. --- Inorganic Chemistry. --- Physical Chemistry. --- Industrial Chemistry/Chemical Engineering. --- Organic Chemistry. --- Inorganic chemistry. --- Physical chemistry. --- Organic chemistry. --- Organic chemistry --- Chemistry --- Chemistry, Industrial --- Engineering, Chemical --- Industrial chemistry --- Engineering --- Chemistry, Technical --- Metallurgy --- Chemistry, Theoretical --- Physical chemistry --- Theoretical chemistry --- Inorganic chemistry --- Inorganic compounds --- Platinum group catalysts --- Formylation --- Hydroxylation
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Biocatalysis, the application of enzymes as catalysts for chemical synthesis, has become an increasingly valuable tool for the synthetic chemist. Enzymatic transformations carried out by enzymes or whole-cell catalysts are used for the production of a wide variety of compounds ranging from bulk to fine chemicals. The primary consideration for the incorporation of biotransformation in a synthetic sequence is regio- and stereocontrol that can be achieved with enzyme-catalyzed reactions. Biotransformations are thus becoming accepted as a method for generating optically pure compounds as well as for developing efficient routes to target compounds. This Special Issue aims to address the main applications of biocatalysts, isolated enzymes, and whole microorganisms in the synthesis of bioactive compounds and their precursors.
Research & information: general --- Biology, life sciences --- 8-hydroxydaidzein --- stable --- soluble --- anti-inflammation --- amylosucrase --- Deinococcus geothermalis --- coumarin --- biotransformation --- filamentous fungi --- selective hydroxylation --- bromination --- chlorination --- pharmaceuticals --- active agent synthesis --- biocatalysis --- haloperoxidase --- halogenase --- glycosyltransferase --- Glycine max (L.) Merr. --- HPLC/MS --- isoflavone aglycone-rich extract --- isoflavone α-glucoside --- alkene cleavage --- aryl alkenes --- basidiomycota --- carotene degradation --- dye-decolorizing peroxidase (DyP) --- manganese --- Komagataella pfaffii --- Pleurotus sapidus --- monoterpenes --- limonene --- glycerol --- mevalonate pathway --- reaction engineering --- bioprocess --- biocatalyst --- two-liquid phase fermentation --- in situ product removal --- lipase --- unsaturated fatty acid --- oxidative cleavage --- oxidation --- adaptation --- UV/NTG mutagenesis --- psychrotrophs --- terpenes
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Biocatalysis, the application of enzymes as catalysts for chemical synthesis, has become an increasingly valuable tool for the synthetic chemist. Enzymatic transformations carried out by enzymes or whole-cell catalysts are used for the production of a wide variety of compounds ranging from bulk to fine chemicals. The primary consideration for the incorporation of biotransformation in a synthetic sequence is regio- and stereocontrol that can be achieved with enzyme-catalyzed reactions. Biotransformations are thus becoming accepted as a method for generating optically pure compounds as well as for developing efficient routes to target compounds. This Special Issue aims to address the main applications of biocatalysts, isolated enzymes, and whole microorganisms in the synthesis of bioactive compounds and their precursors.
8-hydroxydaidzein --- stable --- soluble --- anti-inflammation --- amylosucrase --- Deinococcus geothermalis --- coumarin --- biotransformation --- filamentous fungi --- selective hydroxylation --- bromination --- chlorination --- pharmaceuticals --- active agent synthesis --- biocatalysis --- haloperoxidase --- halogenase --- glycosyltransferase --- Glycine max (L.) Merr. --- HPLC/MS --- isoflavone aglycone-rich extract --- isoflavone α-glucoside --- alkene cleavage --- aryl alkenes --- basidiomycota --- carotene degradation --- dye-decolorizing peroxidase (DyP) --- manganese --- Komagataella pfaffii --- Pleurotus sapidus --- monoterpenes --- limonene --- glycerol --- mevalonate pathway --- reaction engineering --- bioprocess --- biocatalyst --- two-liquid phase fermentation --- in situ product removal --- lipase --- unsaturated fatty acid --- oxidative cleavage --- oxidation --- adaptation --- UV/NTG mutagenesis --- psychrotrophs --- terpenes
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