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Halohydrin Dehalogenase
A halohydrin dehalogenase is an enzyme involved in the bacterial degradation of vicinal halohydrin In organic chemistry a halohydrin (also a haloalcohol or β-halo alcohol) is a functional group in which a halogen and a hydroxyl are bonded to adjacent carbon atoms, which otherwise bear only hydrogen or hydrocarbyl groups (e.g. 2-chloroethan ...s. In several species of bacteria, it catalyses the dehalogenation of halohydrins to produce the corresponding epoxides. Different isoforms of the enzyme fall into one of three groups, A, B or C. Halogenases of the same class are genetically similar, but differ greatly from halogenases from a different group. Currently the most well-studied isoform is HheC which is purified from the bacterial species ''Agrobacterium radiobacter''. The ability to dehalogenate organic compounds as well as form enantiomeric selective epoxides have generated interest in the potential of this enzyme in the biochemical field. Structure Currently of three know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicinal (chemistry)
In chemistry the descriptor vicinal (from Latin ''vicinus'' = neighbor), abbreviated ''vic'', describes any two functional groups bonded to two adjacent carbon atoms (i.e., in a 1,2-relationship). Relation of atoms in a molecule For example, the molecule 2,3-dibromobutane carries two vicinal bromine atoms and 1,3-dibromobutane does not. Mostly, the use of the term vicinal is restricted to two ''identical'' functional groups. Likewise in a ''gem-''dibromide the prefix ''gem'', an abbreviation of geminal, signals that both bromine atoms are bonded to the ''same'' atom (i.e., in a 1,1-relationship). For example, 1,1-dibromobutane is geminal. While comparatively less common, the term hominal has been suggested as a descriptor for groups in a 1,3-relationship. Like other such descriptors as syn, anti, exo or endo, the description ''vicinal'' helps explain how different parts of a molecule are related to each other either structurally or spatially. The vicinal adjective is sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halohydrin
In organic chemistry a halohydrin (also a haloalcohol or β-halo alcohol) is a functional group in which a halogen and a hydroxyl are bonded to adjacent carbon atoms, which otherwise bear only hydrogen or hydrocarbyl groups (e.g. 2-chloroethanol, 3-chloropropane-1,2-diol). The term only applies to saturated motifs, as such compounds like 2-chlorophenol would not normally be considered halohydrins. Megatons of some chlorohydrins, e.g. propylene chlorohydrin, are produced annually as precursors to polymers. Halohydrins may be categorized as chlorohydrins, bromohydrins, fluorohydrins or iodohydrins depending on the halogen present. Synthesis From alkenes Halohydrins are usually prepared by treatment of an alkene with a halogen, in the presence of water. The reaction is a form of electrophilic addition, similar to the halogen addition reaction and proceeds with anti addition, leaving the newly added X and OH groups in a trans configuration. The chemical equation for the conversion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overall Mechanism Of Halohydrin Dehalogenases
Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers". Overalls were originally made of denim, but they can also be made of corduroy, chino cloth, or Leather to name a few. Overalls were invented in the mid to late 1890s by Grace Howard and Jacob W. Davis at Levi Strauss & Co., but they went through an evolution to reach their modern form. Initially only used for protective clothing in work settings, such as farming, welding, working in oil fields, ext. They have also become a garment of high fashion as "potential cult items". Many high fashion brands have released their own spin on overalls. History Beginnings The exact beginnings of the wearing of overalls are unclear, but they are mentioned in literature as early as 1776 as protective working garments commonly worn by slaves. The first evidence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
