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Mycothiol
Mycothiol (MSH or AcCys-GlcN-Ins) is an unusual thiol compound found in the Actinomycetota. It is composed of a cysteine residue with an acetylated amino group linked to glucosamine, which is then linked to inositol. The oxidized, disulfide form of mycothiol (MSSM) is called mycothione, and is reduced to mycothiol by the flavoprotein mycothione reductase. Mycothiol biosynthesis and mycothiol-dependent enzymes such as mycothiol-dependent formaldehyde dehydrogenase and mycothione reductase have been proposed to be good drug targets for the development of treatments for tuberculosis. See also * Glutathione Glutathione (GSH, ) is an organic compound with the chemical formula . It is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources ..., analogous function in other Bacteria * Bacillithiol References {{reflist Mycobacterium tuberculosis is extraordinarily sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycothiol-dependent Formaldehyde Dehydrogenase
In enzymology, a mycothiol-dependent formaldehyde dehydrogenase () is an enzyme that catalyzes the chemical reaction :formaldehyde + mycothiol + NAD+ \rightleftharpoons S-formylmycothiol + NADH + 2 H+ The 3 substrates of this enzyme are formaldehyde, mycothiol, and NAD+, whereas its 3 products are S-formylmycothiol, NADH, and H+. This enzyme catalyses the following chemical reaction This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivi ... of this enzyme class is formaldehyde:NAD+ oxidoreductase (mycothiol-formylating). This enzyme is also called NAD/factor-dependent formaldehyde dehydrogenase or S-(hydroxymethyl)my ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutathione
Glutathione (GSH, ) is an organic compound with the chemical formula . It is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species, free radicals, peroxides, lipid peroxides, and heavy metals. It is a tripeptide with a gamma peptide linkage between the carboxyl group of the glutamate side chain and cysteine. The carboxyl group of the cysteine residue is attached by normal peptide linkage to glycine. Biosynthesis and occurrence Glutathione biosynthesis involves two adenosine triphosphate-dependent steps: *First, γ-glutamylcysteine is synthesized from L-glutamate and L-cysteine. This conversion requires the enzyme glutamate–cysteine ligase (GCL, glutamate cysteine synthase). This reaction is the rate-limiting step in glutathione synthesis. *Second, glycine is added to the C-terminal of γ-glutamylcysteine. This condensation is ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillithiol
Bacillithiol (BSH or Cys-GlcN-mal) is a thiol compound found in ''Bacillus'' species. It is likely involved in maintaining cellular redox balance and plays a role in microbial resistance to the antibiotic fosfomycin. Structure Chemically, it is a glycoside formed between L-cysteinyl-D-glucosamine and malic acid. It was isolated and identified (as its bacillithiol-S- bimane derivative) in 2009 from ''Staphylococcus aureus'' and ''Deinococcus radiodurans'', although it was first detected in 2007, as an unidentified thiol in ''Bacillus anthracis''. The naturally occurring free thiol form of bacillithiol has since been synthesised and characterised along with its biosynthetic precursors and its symmetrical disulfide. Biological role Bacillithiol appears to participate in the sensing of peroxides by ''Bacillus'', but may also substitute for glutathione, which is the most common intracellular thiol in eukaryotes and some bacteria. Some of the genes involved in the biosynthesis of bacill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiol
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic, cabbage or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the smell of natural gas is due to the smell of the thiol used as the odorant. Nomenclature Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinomycetota
The Actinomycetota (or Actinobacteria) are a diverse phylum of Gram-positive bacteria with high GC content. They can be terrestrial or aquatic. They are of great importance to land flora because of their contributions to soil systems. In soil they help to decompose the organic matter of dead organisms so the molecules can be taken up anew by plants. While this role is also played by fungi, Actinomycetota are much smaller and likely do not occupy the same ecological niche. In this role the colonies often grow extensive mycelia, as fungi do, and the name of an important order of the phylum, Actinomycetales (the actinomycetes), reflects that they were long believed to be fungi. Some soil actinomycetota (such as '' Frankia'') live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant's saccharides. Other species, such as many members of the genus ''Mycobacterium'', are important pathogens. Beyond th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine
Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, but both D and L-cysteine are found in nature. LCysteine is a protein monomer in all biota, and D-cysteine acts as a signaling molecule in mammalian nervous systems. Cysteine is named after its discovery in urine, which comes from the urinary bladder or cyst, from Ancient Greek, Greek κύστις ''kýstis'', "bladder". The thiol is susceptible to oxidation to give the disulfide bond, disulfide derivative cystine, which serves an important structural role in many proteins. In this case, the symbol Cyx is sometimes used. The deprotonated form can generally be described by the symbol Cym as well. When used as a food additive, cysteine has the E number E920. Cysteine is Genetic code, encoded by the codo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucosamine
Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the most abundant monosaccharides. Produced commercially by the hydrolysis of shellfish exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat, glucosamine has many names depending on country. Although a common dietary supplement, there is little evidence that it is effective for relief of arthritis or pain, and is not an approved prescription drug in the United States. Dietary supplement Oral glucosamine is a dietary supplement and is not a prescription drug in the United States. Glucosamine is marketed as a supplement to support the structure and function of joints, and the marketing is targeted to people with osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine chondroitin, glu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inositol
In biochemistry, medicine, and related sciences, inositol generally refers to ''myo''-inositol (formerly ''meso''-inositol), the most important stereoisomer of the chemical compound cyclohexane-1,2,3,4,5,6-hexol. Its elemental formula, formula is ; the molecule has a ring of six carbon atoms, each with a hydrogen atom and a hydroxyl group (–OH). In ''myo''-inositol, two of the hydroxyls, neither adjacent nor opposite, lie above the respective hydrogens relative to the mean plane of the ring. The compound is a carbohydrate, specifically a sugar alcohol (as distinct from aldoses like glucose) with half the sweetness of sucrose (table sugar). It is one of the most ancient components of living beings with multiple functions in eukaryotes, including structural lipids and secondary messengers. A human kidney makes about two grams per day from glucose, but other tissues synthesize it too. The highest concentration is in the brain, where it plays an important role in making other neurot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disulfide
In chemistry, a disulfide (or disulphide in British English) is a compound containing a functional group or the anion. The linkage is also called an SS-bond or sometimes a disulfide bridge and usually derived from two thiol groups. In inorganic chemistry, the anion appears in a few rare minerals, but the functional group has tremendous importance in biochemistry. Disulfide bridges formed between thiol groups in two cysteine residues are an important component of the tertiary and quaternary structure of proteins. Compounds of the form are usually called ''persulfides'' instead. Organic disulfides Structure Disulfides have a C–S–S–C dihedral angle approaching 90°. The S–S bond length is 2.03 Å in diphenyl disulfide, similar to that in elemental sulfur. Disulfides are usually symmetric but they can also be unsymmetric. Symmetrical disulfides are compounds of the formula . Most disulfides encountered in organosulfur chemistry are symmetrical disulfides. Unsymme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavoprotein
Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin. These proteins are involved in a wide array of biological processes, including removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair. The flavoproteins are some of the most-studied families of enzymes. Flavoproteins have either FMN ( flavin mononucleotide) or FAD ( flavin adenine dinucleotide) as a prosthetic group or as a cofactor. The flavin is generally tightly bound (as in adrenodoxin reductase, wherein the FAD is buried deeply). About 5-10% of flavoproteins have a covalently linked FAD. Based on the available structural data, FAD-binding sites can be divided into more than 200 different types. 90 flavoproteins are encoded in the human genome; about 84% require FAD and around 16% require FMN, whereas 5 proteins require both. Flavoproteins are mainly located in the mitochondria. Of all flavoproteins, 90% perform redox reactions and the other 10% are transferases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycothione Reductase
In enzymology, a mycothione reductase () is an enzyme that catalyzes the chemical reaction :mycothione + NAD(P)H + H + \rightleftharpoons 2 mycothiol + NADP+ in ''M. tuberculosis'' and other actinomycetes. The 2 substrates of this enzyme are mycothiol and NADPH, whereas 2 molecules of mycothione and NADP+ are formed as products. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivi ... of this enzyme class is mycothiol:NAD(P)+ oxidoreductase. This enzyme is also called mycothiol-disulfide reductase. References * * EC 1.8.1 NADPH-dependent enzymes NADH-dependent enzymes Enzymes of unknown structure {{1.8-enzy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets are proteins and nucleic acids. The definition is context-dependent, and can refer to the biological target of a pharmacologically active drug compound, the receptor target of a hormone (like insulin), or some other target of an external stimulus. Biological targets are most commonly proteins such as enzymes, ion channels, and receptors. Mechanism The external stimulus (''i.e.'', the drug or ligand) physically binds to ("hits") the biological target. The interaction between the substance and the target may be: * noncovalent – A relatively weak interaction between the stimulus and the target where no chemical bond is formed between the two interacting partners and hence the interaction is completely reversible. * reversible coval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
