Mycothiol (MSH or AcCys-GlcN-Ins) is an unusual

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 grou ...

compound found in the

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 t ...

. It is composed of a

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 ...

residue with an acetylated amino group linked to

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 mo ...

, which is then linked to

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 oxidized,

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 inorg ...

form of mycothiol (MSSM) is called mycothione, and is reduced to mycothiol by the

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. ...

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 my ...

. Mycothiol biosynthesis and mycothiol-dependent enzymes such as

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 formalde ...

and mycothione reductase have been proposed to be good

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 ...

s for the development of treatments for

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

References

{{reflist Mycobacterium tuberculosis is extraordinarily sensitive to killing by a vitamin C-induced Fenton reaction Published 21 May 2013. Nature Communications4, Article number:1881 doi:10.1038/ncomms2898

External links

The Biochemistry of Pathogens: The metabolism and function of mycothiol in the mycobacteria.
Thiols Acetamides Propionamides Tetrahydropyrans

See also

References

External links