scispace - formally typeset
Search or ask a question
Topic

Chitin

About: Chitin is a research topic. Over the lifetime, 6590 publications have been published within this topic receiving 253993 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: This work shows that ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, and identifies three sets of differentially regulated genes that confer a significant growth advantage to V. cholerae on a chitin surface.
Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin.

522 citations

Journal ArticleDOI
TL;DR: Chitosan, a deacetylated form of chitin, inhibited the growth of many fungi, including plant and animal pathogens, and was insensitive to its fungicidal effects.

518 citations

Journal ArticleDOI
01 Jun 2012-Science
TL;DR: The data support the notion that chitin-induced AtCERK1 dimerization is critical for its activation and suggest that the biological response requires dimerisation of the receptor when it binds a chit in oligomer at least seven or eight subunits long.
Abstract: Pattern recognition receptors confer plant resistance to pathogen infection by recognizing the conserved pathogen-associated molecular patterns. The cell surface receptor chitin elicitor receptor kinase 1 of Arabidopsis (AtCERK1) directly binds chitin through its lysine motif (LysM)-containing ectodomain (AtCERK1-ECD) to activate immune responses. The crystal structure that we solved of an AtCERK1-ECD complexed with a chitin pentamer reveals that their interaction is primarily mediated by a LysM and three chitin residues. By acting as a bivalent ligand, a chitin octamer induces AtCERK1-ECD dimerization that is inhibited by shorter chitin oligomers. A mutation attenuating chitin-induced AtCERK1-ECD dimerization or formation of nonproductive AtCERK1 dimer by overexpression of AtCERK1-ECD compromises AtCERK1-mediated signaling in plant cells. Together, our data support the notion that chitin-induced AtCERK1 dimerization is critical for its activation.

512 citations

Journal ArticleDOI
TL;DR: The uniqueness of chitosan among polysaccharides is underlined in terms of susceptibility to enzymatic depolymerization, cationicity, supply of cell-activating oligomers, and supply of N-acetylglucosamine for rebuilding of other biopolymers.
Abstract: Three cases are presented where modified chitins have been extensively administered to volunteers, as dressings for wounded soft and bone tissues, as anticholesterolemic dietary foods, and in the controlled delivery of anti-inflammatory drugs. The interactions of the modified chitins with human enzymes is critically examined. In the context of drug carrier resorption and wound healing, chitooligomers and monomers, generated by lysozyme, N-acetylglucosaminidase and human chitinase, activate macrophages and stimulate fibroblasts, respectively; the effects are production of smooth, vascularized and physiologically normal tissues. In the dietary food area, lipase, amylase, 3-hydroxy-3-methylglutaryl CoA reductase, glucokinase and the enzymes of prostaglandin synthesis are involved in the oral administration of chitosan: lipid adsorption is depressed mainly because of the physical form of the chitosan-lipid aggregates, which are unsuitable as substrates. When chitosan is used as a drug carrier, chitosan-drug complexes are present. The uniqueness of chitosan among polysaccharides is underlined in terms of susceptibility to enzymatic depolymerization, cationicity, supply of cell-activating oligomers, and supply of N-acetylglucosamine for rebuilding of other biopolymers. Advances in molecular recognition and biocompatibility are also presented.

503 citations

Journal ArticleDOI
TL;DR: In this paper, the authors extracted chitin in the α and the β forms from different marine crustacean from the Arabian Gulf, and the contents of the various exoskeletons have been analyzed and the percent of the inorganic salt (including the various elements present), protein and the chitins was determined.

501 citations


Network Information
Related Topics (5)
Cellulose
59K papers, 1.4M citations
87% related
Enzyme
32.8K papers, 1.1M citations
81% related
Amino acid
124.9K papers, 4M citations
80% related
Fermentation
68.8K papers, 1.2M citations
80% related
Saccharomyces cerevisiae
32.1K papers, 1.6M citations
80% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023434
2022868
2021271
2020354
2019333
2018271