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Chitin
About: Chitin is a research topic. Over the lifetime, 6590 publications have been published within this topic receiving 253993 citations.
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TL;DR: The recent isolation and sequencing of insect CS genes should help in elucidating various aspects of chitin biochemistry and inhibition, and are expected to shed light on the mode of action of acylurea insecticides.
Abstract: Chitin is an abundant biologically important aminopolysaccharide composed of N-acetyl-D-glucosamine units Individual polymers, which are synthesized intracellularly by chitin synthase (CS), a membrane-bound glycosyl transferase, are translocated across the plasma membrane and coalesce to form rigid crystallites These crystallites, inter alia, are integral parts of septa and cell walls in yeast and filamentous fungi, respectively, and of cuticles in invertebrates, notably crustaceans and insects Despite decades of intensive research, many events associated with the complexity of chitin formation and deposition are still obscure, or only partially understood The list includes the hormonal control of CS at the transcriptional and translational levels as well as the post-translational CS packaging; trafficking and guidance of CS clusters to proper sites in the cells and their intricate insertion into the plasma membranes; activation of the catalytic step and its control or modulation; and translocation of chitin chains across cell membranes, their orientation, fibrillogenesis and association with other extracellular structural components such as polysaccharides (fungi) and cuticular proteins (insects) Also the precise biochemical lesions inflicted by CS inhibitors, such as the acylurea insect growth regulators, are largely unclear The recent isolation and sequencing of insect CS genes should help in elucidating various aspects of chitin biochemistry and inhibition In particular, the large number of transmembrane segments, characteristic of the insect CS, are speculated to be involved in chitin translocation and are expected to shed light on the mode of action of acylurea insecticides
201 citations
TL;DR: A core chitin degradation pathway is proposed based on comparison of 19 Vibrio and Photobacterium genomes with a detailed metabolic map assembled for V. cholerae from published biochemical, genomic, and transcriptomic results.
Abstract: Vibrionaceae are regarded as important marine chitin degraders, and attachment to chitin regulates important biological functions; yet, the degree of chitin pathway conservation in Vibrionaceae is unknown. Here, a core chitin degradation pathway is proposed based on comparison of 19 Vibrio and Photobacterium genomes with a detailed metabolic map assembled for V. cholerae from published biochemical, genomic, and transcriptomic results. Further, to assess whether chitin degradation is a conserved property of Vibrionaceae, a set of 54 strains from 32 taxa were tested for the ability to grow on various forms of chitin. All strains grew on N-acetylglucosamine (GlcNAc), the monomer of chitin. The majority of isolates grew on α (crab shell) and β (squid pen) chitin and contained chitinase A (chiA) genes. chiA sequencing and phylogenetic analysis suggest that this gene is a good indicator of chitin metabolism but appears subject to horizontal gene transfer and duplication. Overall, chitin metabolism appears to be a core function of Vibrionaceae, but individual pathway components exhibit dynamic evolutionary histories.
200 citations
TL;DR: The binding features observed in the complex structures suggest that either chitin or a closely related oligosaccharide could act as the physiological ligand for HCgp-39.
199 citations
TL;DR: The crystal structure of the human chitotriosidase and complexes with a chitooligosaccharide and allosamidin reveal an elongated active site cleft, compatible with the binding of long chitin polymers, and explain the inactivation of the enzyme through an inherited genetic deficiency.
199 citations
Book•
01 Jan 2001
TL;DR: This work discusses chitin's role as a biomaterial, its use in biomedical applications, and the implications of in vitro enzyme biodegradation studies on chitIn to humans and biomedical applications.
Abstract: The Relevance Of Chitin. Chitin: from then to now. Definitions. Obscurity. From waste to niche materials. Biomedical applications. References. Chitin Biomedical Applications. Biomedical technology. Wound dressings. Chitin-based wound dressings. Chitin-based wound dressings patents. Chitin-blood interactions. Bone substitutes. Chitin-based bone substitutes. Chitin-based bone substitutes patents. Tissue engineering. Drug delivery. Chitin-based drug delivery systems. General forms. Microspheres. Chitin-based drug delivery patents. Relevance of chitin biomedical applications. References. Chitin As A Biomaterial. Biomaterials. Chitin's role as a biomaterial. Bio-stable chitin. Biodegradable-chitin. Biosynthesis and biodegradation of chitin in nature. Biodegradation of chitin in humans. Implications of in vitro enzyme biodegradation studies on chitin to humans and biomedical applications. Biodegradation lifetime and fate of biodegradation products. Inference. References. Biocompatibility Issues. What is biocompatibility? Is chitin really biocompatible? Survey of the biocompatibility studies on chitin. Outstanding matters. References. The Sources And Production Of Chitin. Sources of chitin. Chitin production. Isolation of chitin. Isolation of chitin from shellfish. Demineralizaton . Deproteinization. Deacetylation of chitin into chitosan. Physical appearance. Isolation of chitin from algae and fungi. Consequence. References. The Structural Properties Of Chitin As It Is Known Today. Introduction. Solid-state structure. Characterization of chitin properties. Degree of N-Acetylation (DA)/Deacetylation (DD). Molecular weight determination. Outcome. References. The Chemistry Of Chitin As It Is Known Today . Appendix I. Appendix II. Appendix III. Subject index. Motivation. Alkali-chitin. Can chitin compete? Significance of the US-FDA approval process.Tosyl-chitin. Direct reactions -chitin. Epitaph or glory? References.Chitosan. Fibers and gels. Random or block distribution of N-Acetyl groups during deacetylation reactions oligomerization by chemical and enzymatic means. Chemical synthesis. Hyaluronic acid.Competition from other biopolymers.Implications. Collagen.Mission requirements. References. Chondroitin sulfate. The Regulatory Road To Approval For Chitin. The patient is first.Chitin's regulatory status.Identifiable targets.Curre
199 citations