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Chitinase

About: Chitinase is a research topic. Over the lifetime, 4690 publications have been published within this topic receiving 161786 citations. The topic is also known as: 1,4-beta-poly-N-acetylglucosaminidase & poly-beta-glucosaminidase.


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Journal ArticleDOI
TL;DR: The extensive secretome analysis of T. harzianum highlights the importance of this fungus as a rich source of hydrolytic enzymes for bioconversion and biocontrol applications.
Abstract: Trichoderma harzianum is a mycoparasitic filamentous fungus that produces and secretes a wide range of extracellular hydrolytic enzymes used in cell wall degradation. Due to its potential in biomass conversion, T. harzianum draws great attention from biofuel and biocontrol industries and research. Here, we report an extensive secretome analysis of T. harzianum. The fungus was grown on cellulose medium, and its secretome was analyzed by a combination of enzymology, 2DE, MALDI-MS and -MS/MS (Autoflex II), and LC-MS/MS (LTQ-Orbitrap XL). A total of 56 proteins were identified using high-resolution MS. Interestingly, although cellulases were found, the major hydrolytic enzymes secreted in the cellulose medium were chitinases and endochitinases, which may reflect the biocontrol feature of T. harzianum. The glycoside hydrolase family, including chitinases (EC 3.2.1.14), endo-N-acetylglucosaminidases (EC 3.2.1.96), hexosaminidases (EC 3.2.1.52), galactosidases (EC 3.2.1.23), xylanases (EC 3.2.1.8), exo-1,3-glucanases (EC 3.2.1.58), endoglucanases (EC 3.2.1.4), xylosidases (EC 3.2.1.37), α-L-arabinofuranosidase (EC 3.2.1.55), N-acetylhexosaminidases (EC 3.2.1.52), and other enzymes represented 51.36% of the total secretome. Few representatives were classified in the protease family (8.90%). Others (17.60%) are mostly intracellular proteins. A considerable part of the secretome was composed of hypothetical proteins (22.14%), probably because of the absence of an annotated T. harzianum genome. The T. harzianum secretome composition highlights the importance of this fungus as a rich source of hydrolytic enzymes for bioconversion and biocontrol applications.

59 citations

Journal ArticleDOI
TL;DR: The results suggested that the PmChi2 was likely involved in molting while the others might function in the digestion of chitinous foods, and the recombinant Pmchi1 over-produced from Escherichia coli had its optimal pH 5 but it was most stable at neutral pH.
Abstract: Chitinases are essential enzymes for crustaceans and animal alike for their molting and digestion of foods containing chitin. From the Penaeus monodon EST database, cDNA contigs and singletons for three chitinases, namely PmChi1, 2 and 3, were identified. The complete sequences for the mature PmChi1, 3 and partial PmChi2 were amplified and cloned. The reading frames of PmChi1 and 3 encoded mature proteins of 644 and 468 amino acids with calculated molecular masses of 72.4 and 51.9 kDa, respectively. The amino acid sequence comparison among the penaeid chitinases revealed homology around 90%. Therefore, they were grouped together along with those of other crustaceans and insects into three groups separated from those of mammals. PmChi1, 2 and 3 were expressed mainly in hepatopancreas, gill and hepatopancreas, respectively, though small amounts were expressed in other tissues. After molting, only the expression of PmChi2 was down-regulated, while the expression of PmChi1 and 3 was relatively unchanged. The results suggested that the PmChi2 was likely involved in molting while the others might function in the digestion of chitinous foods. The recombinant PmChi1 (rPmChi1) over-produced from Escherichia coli had its optimal pH 5 but it was most stable at neutral pH. Interestingly, the optimal temperature was relatively high at 55 °C. Nevertheless, it was stable at lower temperature below 40 °C. The rPmChi1 preferentially hydrolyzed the more soluble substrates like partially N-acetylated chitin (PNAC) and colloidal chitin from shrimp shell as compared to the β-chitin from squid pen.

58 citations

Journal ArticleDOI
TL;DR: The high chitinolytic activity of strain FPU-7 and the chitinases may be useful for environmentally friendly processing of chitIn in the manufacture of food and/or medicine.
Abstract: Chitin, a major component of fungal cell walls and invertebrate cuticles, is an exceedingly abundant polysaccharide, ranking next to cellulose. Industrial demand for chitin and its degradation products as raw materials for fine chemical products is increasing. A bacterium with high chitin-decomposing activity, Paenibacillus sp. strain FPU-7, was isolated from soil by using a screening medium containing α-chitin powder. Although FPU-7 secreted several extracellular chitinases and thoroughly digested the powder, the extracellular fluid alone broke them down incompletely. Based on expression cloning and phylogenetic analysis, at least seven family 18 chitinase genes were found in the FPU-7 genome. Interestingly, the product of only one gene (chiW) was identified as possessing three S-layer homology (SLH) domains and two glycosyl hydrolase family 18 catalytic domains. Since SLH domains are known to function as anchors to the Gram-positive bacterial cell surface, ChiW was suggested to be a novel multimodular surface-expressed enzyme and to play an important role in the complete degradation of chitin. Indeed, the ChiW protein was localized on the cell surface. Each of the seven chitinase genes (chiA to chiF and chiW) was cloned and expressed in Escherichia coli cells for biochemical characterization of their products. In particular, ChiE and ChiW showed high activity for insoluble chitin. The high chitinolytic activity of strain FPU-7 and the chitinases may be useful for environmentally friendly processing of chitin in the manufacture of food and/or medicine.

58 citations

Journal ArticleDOI
TL;DR: WAMPs represent novel protease inhibitors that are active against fungal metalloproteases, suggesting that fungalysin plays an important role in fungal development and a novel molecular mechanism of dynamic interplay between host defense molecules and fungal virulence factors is suggested.
Abstract: The multilayered plant immune system relies on rapid recognition of pathogen-associated molecular patterns followed by activation of defense-related genes, resulting in the reinforcement of plant cell walls and the production of antimicrobial compounds To suppress plant defense, fungi secrete effectors, including a recently discovered Zn-metalloproteinase from Fusarium verticillioides, named fungalysin Fv-cmp This proteinase cleaves class IV chitinases, which are plant defense proteins that bind and degrade chitin of fungal cell walls In this study, we investigated plant responses to such pathogen invasion, and discovered novel inhibitors of fungalysin We produced several recombinant hevein-like antimicrobial peptides named wheat antimicrobial peptides (WAMPs) containing different amino acids (Ala, Lys, Glu, and Asn) at the nonconserved position 34 An additional Ser at the site of fungalysin proteolysis makes the peptides resistant to the protease Moreover, an equal molar concentration of WAMP-1b or WAMP-2 to chitinase was sufficient to block the fungalysin activity, keeping the chitinase intact Thus, WAMPs represent novel protease inhibitors that are active against fungal metalloproteases According to in vitro antifungal assays WAMPs directly inhibited hyphal elongation, suggesting that fungalysin plays an important role in fungal development A novel molecular mechanism of dynamic interplay between host defense molecules and fungal virulence factors is suggested

58 citations

Journal ArticleDOI
TL;DR: The CTS1-2 gene has been evaluated for its in planta antifungal activity by constitutive overexpression in tobacco plants to assess its potential to increase the plant's defence against fungal pathogens.
Abstract: The Saccharomyces cerevisiae chitinase, encoded by the CTS1-2 gene has recently been confirmed by in vitro tests to possess antifungal abilities. In this study, the CTS1-2 gene has been evaluated for its in planta antifungal activity by constitutive overexpression in tobacco plants to assess its potential to increase the plant's defence against fungal pathogens. Transgenic tobacco plants, generated by Agrobacterium-mediated transformation, showed stable integration and inheritance of the transgene. Northern blot analyses conducted on the transgenic tobacco plants confirmed transgene expression. Leaf extracts from the transgenic lines inhibited Botrytis cinerea spore germination and hyphal growth by up to 70% in a quantitative in vitro assay, leading to severe physical damage on the hyphae. Several of the F1 progeny lines were challenged with the fungal pathogen, B. cinerea, in a detached leaf infection assay, showing a decrease in susceptibility ranging from 50 to 70%. The plant lines that showed increased disease tolerance were also shown to have higher chitinase activities.

58 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023186
2022337
2021148
2020172
2019154
2018152