Disease relevance of Chit1

• Legionella pneumophila type II secretome reveals unique exoproteins and a chitinase that promotes bacterial persistence in the lung [1].
• Polymorphisms and haplotypes of acid mammalian chitinase are associated with bronchial asthma [2].
• The secreted CTS1 chitinase has also been shown to react with patient anti-Coccidioides complement-fixing (CF) antibody and is a valuable aid in the serodiagnosis of coccidioidomycosis [3].
• Chitinase has been suggested to play a pivotal role in autolysis of the parasitic cell wall of Coccidioides immitis during the asexual reproductive cycle (endosporulation) of this systemic pathogen [3].
• T helper cell-recognized epitopes were determined in chitinase of Onchocerca volvulus, a vaccine candidate protein [4].

High impact information on Chit1

• Because a chitinase had not been previously reported in Legionella, we determined that wild type secretes activity against both p-nitrophenyl triacetyl chitotriose and glycol chitin [1].
• Since in at least one vertebrate system hyaluronic acid formation can be inhibited by a pure chitinase, it seems possible that chitin oligosaccharides serve as primers for hyaluronic acid synthesis [5].
• The deduced amino acid sequence shows a 31% amino acid homology to Aedes aegypti chitinase and a multidomain structure containing one chitin binding peritrophin A domain and two glycosyl hydrolase family 18 chitin binding domains [6].
• A cDNA encoding tick chitinase was cloned from a cDNA library of mRNA from Haemaphysalis longicornis eggs and designated as CHT1 cDNA [6].
• The CHT1 cDNA has an ELR motif for chemokine-mediated angiogenesis and appears to be a chitinase of the chemokine family [6].

Biological context of Chit1

• The predicted amino acid sequence is highly homologous to that of human chitotriosidase and to that of mouse acidic mammalian chitinase [7].
• The open reading frame of this cDNA predicts a protein of 464 amino acids with a typical chitinase structure, including a signal peptide, a highly conserved catalytic domain and a chitin-binding domain [7].
• ECF-L retains those amino acids highly conserved among chitinase family proteins, but Asp and Glu residues essential for the proton donation in hydrolysis were replaced by Asn and Gln, respectively [8].
• However, loss of CTS1 function had no effect on virulence or endosporulation [3].
• This resulted in homologous integration of a pAN7.1 plasmid construct that contained a 1.1-kb fragment of the chitinase gene into the chromosomal DNA of C. immitis [3].

Anatomical context of Chit1

• Human cartilage gp-39, a major secretory product of articular chondrocytes and synovial cells, is a mammalian member of a chitinase protein family [9].
• Suppressive subtractive hybridization analysis revealed that eosinophil chemotactic factor by T lymphocytes (ECF-L), a mouse chitinase family protein, was selectively expressed in the lungs of mice with AHR [10].
• A member of the chitinase protein family, oviduct-specific glycoprotein (OGP), can directly associate with gametes or with the early embryo in the oviduct [11].
• Two distinct chitinases have been identified in mammals: a phagocyte-specific enzyme named chitotriosidase and an acidic mammalian chitinase (AMCase) expressed in the lungs and gastrointestinal tract [12].
• A total of eleven hybridomas which secrete antibodies against chitinase A1 were established [13].

Associations of Chit1 with chemical compounds

• Recombinant expression of the cloned cDNA demonstrated that the encoded protein is secreted and has chitinolytic activity that is sensitive to the specific chitinase inhibitor allosamidin and has the ability to bind to chitin particles [7].
• The human protein does not possess any glycosidic activity against chitinase substrates, arguing against any function as an endoglycosidase with specificity for N-acetylglucosamine [9].
• Ym is one of the chitinase family proteins, which are widely distributed in mammalian bodies and can bind glycosaminoglycans such as heparin/heparan sulfate [14].
• From the seeds of the pinto bean (Phaseolus vulgaris cv. pinto), a chitinase and a novel antifungal protein, both with the ability of markedly augmenting nitrite production by murine peritoneal macrophages, were isolated [15].
• In this study, 166Ho was complexed to chitosan (Chit) which decreases the distribution of Ho into other tissues when applied intrahepatically [16].

Other interactions of Chit1

• Following re-crystallization at neutral pH, the crystals were identified as the chitinase-like protein Ym1, expressed in organs of the lymphoreticular system, the lung, and distal stomach [17].
• Down-regulation of chitinase 3- and-4 gene expression likely reflects cytokines produced by T-helper 2 (Th2) type cells [18].
• The mature ChiA is a modular enzyme composed of a family-18 catalytic domain responsible for chitinase activity, two cadherin-like domains, and a chitin-binding domain [19].
• Immunohistochemical Detection of Ym1/Ym2 Chitinase-like Lectins Associated with Hyalinosis and Polypoid Adenomas of the Transitional Epithelium in a Mouse with Acute Myeloid Leukemia [20].
• Disintegration tests on the ARBC using the enzymes (lysozyme, chitinase and phospholipase C), that can digest the components of the ARBC membrane, suggested that the membrane has a structure in which the phospholipid layer is covered by a mesh of CM chitin molecules [21].

Analytical, diagnostic and therapeutic context of Chit1

• Further, results of coupled immunoprecipitation/enzyme activity experiments demonstrated that the LmexCht1 chimeric protein was secreted/released by these transfected L. mexicana parasites and that it possessed functional chitinase enzyme activity [22].
• This conclusion is based on the finding that chitinase specifically destroys the cyst wall, as revealed by electron microscopy [23].
• Cellular expression of murine Ym1 and Ym2, chitinase family proteins, as revealed by in situ hybridization and immunohistochemistry [14].
• Chitinase from Paracoccidioides brasiliensis: molecular cloning, structural, phylogenetic, expression and activity analysis [24].
• Chitinase assay in gels after SDS-PAGE was a very sensitive method that allowed us to detect two chitinases with distinct molecular weights in the mosquito gut [25].

References