Lipomannan is a

mycobacterium ''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (''Mycobacterium tuberculo ...

immune

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

. In addition, it is a major constituent of the mycobacterium cell wall. This

glycoconjugate In molecular biology and biochemistry, glycoconjugates are the classification family for carbohydrates – referred to as glycans – which are covalently linked with chemical species such as proteins, peptides, lipids, and other compounds. Glyc ...

is a

virulence factor Virulence factors (preferably known as pathogenicity factors or effectors in botany) are cellular structures, molecules and regulatory systems that enable microbial pathogens (bacteria, viruses, fungi, and protozoa) to achieve the following: * c ...

that plays a key role in the

human immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as cancer cells, parasitic worms, and also objects such a ...

via interaction with various immune cells. It is also considered to be a precursor of lipoarabinomannans. It is a trigger for TLR 2. It consists of an α-linked mannan, which consists of 50–70 residues, with some branches points linked glycosidically to a diglyceride of which the fatty acids are similar to those of the whole cell lipid. In addition,

succinic acid Succinic acid () is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fum ...

residues are present as O-acyl substituents on about one in four of the mannose residues, the terminal

carboxyl group In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl group (e.g. ...

of the succinic acid providing the whole polymer with a considerable number of acidic functions. Lipomannan has functional components that resemble lipoteichoic acids; a lipophilic region and a hydrophilic portion with frequent acid groups. Lipomannan is a phosphorylated

polysaccharide Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wat ...

associated with the cell envelope and is considered to be the multimannosylated form of PIM which is primarily located in the plasma membrane. Structurally, LM is composed of two segments: a PI anchor to which is attached an α-D-mannan domain; both play key roles in inducing cytokine production by phagocytic cells. Mannose core consists of a linear α(1-6)-linked mannan backbone extending from the c-6 of the

myo-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 formula is ; the molecule has ...

; the mannan chains is further substituted by α-(1-2) man-p side branches.

References

External links

* Receptor agonists {{biochem-stub