Chitin belongs to a group of polysaccharide carbohydrates. Carbohydrates are organic compound s comprised of carbon , hydrogen , and oxygen , usually in the ratio of They are one of the major classes of biomolecule s.
Polysaccharide are carbohydrates made up of multiple saccharide units. Some of them serve as energy fuel whereas others have structural functions. The discovery of chitin was credited to the French scientist Henri Braconnot in He was the first to describe the compound that he extracted from mushrooms and is insoluble in sulfuric acid.
He named it fungine. Later, the name of the compound was changed to chitin. It has several applications since it is nontoxic, biodegradable thus, more environmental friendly , and has antimicrobial properties.
For instance, it has been used in surgical stitches that dissolve over time. It has also been used as an additive in certain creams and cosmetics. Chitin resembles keratin protein component in human hair and nail s in structural function. Nonetheless, it differs from keratin through its carbohydrate polysaccharide structural component. In terms of structure, it resembles cellulose. Chitin is a modified carbohydrate for containing nitrogen. In cellulose though, the monomers are glucose units.
Furthermore, chitin has an acetylamine group instead of a hydroxyl group on each monomer. This enables more opportunities of hydrogen bonding between polymers in chitin, and thereby renders increased structural strength.
Mol Genet Genomics. Stimulation of chitin synthesis rescues Candida albicans from echinocandins. PLoS Pathog. The paper also describes how activation of the chitin compensatory response can overcome the otherwise lethal effects of mutations in the normally essential CHS1 gene of C. Fortwendel J. Transcriptional regulation of chitin synthases by calcineurin controls paradoxical growth of Aspergillus fumigatus in response to caspofungin. Antimicrob Agents Chemother. Individual chitin synthase enzymes synthesize microfibrils of differing structure at specific locations in the Candida albicans cell wall.
Fukuda K. Class III chitin synthase ChsB of Aspergillus nidulans localizes at the sites of polarized cell wall synthesis and is required for conidial development. Blankenship J. An extensive circuitry for cell wall regulation in Candida albicans. Teh E. Cell Cycle. Martinez-Rucobo F. Yeast chitin synthase 2 activity is modulated by proteolysis and phosphorylation. Biochem J. Beltrao P. Evolution of phosphoregulation: comparison of phosphorylation patterns across yeast species.
PLoS Biol. Phosphorylation regulates polarisation of chitin synthesis in Candida albicans. J Cell Sci. Chuang J. Differential trafficking and timed localization of two chitin synthase proteins. Chs2p and Chs3p. J Cell Biol. Chitosomes: past, present and future. Schorr M. The phosphoinositide phosphatase Sac1p controls trafficking of the yeast Chs3p chitin synthase. Curr Biol. Reyes A. DeMarini D. A septin-based hierarchy of proteins required for localized deposition of chitin in the Saccharomyces cerevisiae cell wall.
Kozubowski L. A Bni4-Glc7 phosphatase complex that recruits chitin synthase to the site of bud emergence. Larson J. Protein phosphatase type 1 directs chitin synthesis at the bud neck in Saccharomyces cerevisiae. Changes in Bni4 localization induced by cell stress in Saccharomyces cerevisiae. Liu H. Wangiella Exophiala dermatitidis WdChs5p, a class V chitin synthase, is essential for sustained cell growth at temperature of infection.
Takeshita N. Aspergillus nidulans class V and VI chitin synthases CsmA and CsmB, each with a myosin motor-like domain, perform compensatory functions that are essential for hyphal tip growth. Fujiwara M. A novel fungal gene encoding chitin synthase with a myosin motor-like domain. Biochem Biophys Res Commun.
Abramczyk D. Cytolocalization of the class V chitin synthase in the yeast, hyphal and sclerotic morphotypes of Wangiella Exophiala dermatitidis. Tsuizaki M. Myosin motor-like domain of the class VI chitin synthase CsmB is essential to its functions in Aspergillus nidulans. Biosci Biotechnol Biochem. CsmA, a class V chitin synthase with a myosin motor-like domain, is localized through direct interaction with the actin cytoskeleton in Aspergillus nidulans.
Reid D. Pattern recognition: recent insights from Dectin Curr Opin Immunol. Netea M. Immune sensing of Candida albicans requires cooperative recognition of mannans and glucans by lectin and Toll-like receptors. J Clin Invest. An integrated model of the recognition of Candida albicans by the innate immune system.
Nat Rev Microbiol. Rappleye C. Histoplasma capsulatum alpha- 1,3 -glucan blocks innate immune recognition by the beta-glucan receptor. Lee C. Chitin regulation of immune responses: an old molecule with new roles. Da Silva C. J Immunol. Zhu Z. Acidic mammalian chitinase in asthmatic Th2 inflammation and IL pathway activation. Gordon-Thomson C. Chitotriosidase and gene therapy for fungal infections. Cell Mol Life Sci. Chitin, chitinases and chitinase-like proteins in allergic inflammation and tissue remodeling.
Yonsei Med J. Reese T. Chitin induces accumulation in tissue of innate immune cells associated with allergy. Accumulation of these immune cells was abolished in the presence of human chitinase.
This is the first report directly linking chitin to allergy. Fungal LysM effectors: extinguishers of host immunity? Trends Microbiol. Cash H. Symbiotic bacteria direct expression of an intestinal bactericidal lectin.
Bacterial peptidoglycan triggers Candida albicans hyphal growth by directly activating the adenylyl cyclase Cyr1p. Cell Host Microbe.
Schlosser A. Here, the authors show that FIBCD1 binds acetylated compounds such as chitin with high-affinity in a calcium-dependent manner. This receptor, however, does not recognise deacetylated compounds, leaving the way open for investigations to find additional chitin and chitosan receptors. The full tissue expression profile for this receptor also remains to be determined. Villiers C.
This allows for increased hydrogen bonding between adjacent polymers, giving the chitin-polymer matrix increased strength.
In its unmodified form, chitin is translucent, pliable, resilient and quite tough. In arthropods, however, it is often modified, becoming embedded in a hardened proteinaceous matrix, which forms much of the exoskeleton.
In its pure form it's leathery, but when encrusted in calcium carbonate it becomes much harder. Chitin is one of many naturally occurring polymers. Its breakdown may be catalyzed by enzymes called chitinases , secreted by microorganisms such as bacteria and fungi, and produced by some plants.
Some of these microorganisms have receptors to simple sugars from the decomposition of chitin. If chitin is detected, they then produce enzymes to digest it by cleaving the glycosidic bonds in order to convert it to simple sugars and ammonia. Chemically, chitin is closely related to chitosan a more water-soluble derivative of chitin. It is also closely related to cellulose in that it is a long unbranched chain of glucose derivatives.
Both materials contribute structure and strength, protecting the organism. The English word "chitin" comes from the French word "chitine", which first appeared in A similar word, "chiton", refers to a marine animal with a protective shell also known as a "sea cradle". Chitin is used industrially in many processes. It is used in water purification , and as an additive to thicken and stabilize foods and pharmaceuticals.
It also acts as a binder in dyes, fabrics, and adhesives. Industrial separation membranes and ion-exchange resins can be made from chitin. Processes to size and strengthen paper employ chitin. Chitin's properties as a flexible and strong material make it favourable as surgical thread.
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