Mycothiol
Encyclopedia
Mycothiol is an unusual thiol
compound found in the Actinobacteria
. 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
.
Thiol
In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...
compound found in the Actinobacteria
Actinobacteria
Actinobacteria are a group of Gram-positive bacteria with high guanine and cytosine content. They can be terrestrial or aquatic. Actinobacteria is one of the dominant phyla of the bacteria....
. It is composed of a cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
residue with an acetylated amino group linked to glucosamine
Glucosamine
Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, cell walls in fungi and...
, which is then linked to inositol
Inositol
Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound with formula 6126 or 6, a sixfold alcohol of cyclohexane. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is cis-1,2,3,5-trans-4,6-cyclohexanehexol, or myo-inositol...
. The oxidized, disulfide
Disulfide
In chemistry, a disulfide usually refers to the structural unit composed of a linked pair of sulfur atoms. Disulfide usually refer to a chemical compound that contains a disulfide bond, such as diphenyl disulfide, C6H5S-SC6H5....
form of mycothiol (MSSM) is called mycothione, and is reduced to mycothiol by the flavoprotein
Flavoprotein
Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin: the flavin adenine dinucleotide or flavin mononucleotide ....
mycothione reductase
Mycothione reductase
In enzymology, a mycothione reductase is an enzyme that catalyzes the chemical reactionin 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...
. Mycothiol biosynthesis and mycothiol-dependent enzymes such as mycothiol-dependent formaldehyde dehydrogenase
Mycothiol-dependent formaldehyde dehydrogenase
In enzymology, a mycothiol-dependent formaldehyde dehydrogenase is an enzyme that catalyzes the chemical reactionThe 3 substrates of this enzyme are formaldehyde, mycothiol, and NAD+, whereas its 3 products are S-formylmycothiol, NADH, and H+....
and mycothione reductase have been proposed to be good drug targets for the development of treatments for tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
.