Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Salivary gland plasticity was a significant adaptive feature in the mammalian radiation. This plasticity is reflected in remarkable and well-documented interspecific phenotypic variation in gland ultrastructure and in the chemical components of saliva. However, comparative data are still too sparse for determination of evolutionary trends that combine phenotypic patterns with evolutionary history and the actual secretory products. Although our theoretical approach assumes that natural selection has taken advantage of salivary gland plasticity in gene regulation, gland development, and secretory cell organelles and processes, it still is difficult to delineate the biological roles of secretory products in the context of ecological adaptation. In the present investigation we used immunohistochemical techniques and a polyclonal antiserum against lysozyme to compare the parotid and principal submandibular glands in a set of 12 species of microchiropteran bats. With this data set we used comparative methods and phylogenetic trees to develop the foundations for testable hypotheses about the molecular genetics and adaptive significance of lysozyme production in bats. By comparing immunohistochemical results with ultrastructure, lysozyme-like immunoreactivity was associated with serous secretory granules in parotid gland acinar calls, parotid gland intercalated duct cells, and submandibular gland demilune cells. Lysozyme production in submandibular gland demilune cells marks a point of evolutionary divergence between three families of insectivorous bats and four families composed of species with diverse diets (ranging from carnivory to nectarivory). In terms of diet, lysozyme-like immunoreactivity corresponded most strongly with feeding on hard-bodied insects, leading to the hypothesis that lysozyme serves as an important chitinase in bat saliva.
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PMID:Plasticity and patterns of evolution in mammalian salivary glands: comparative immunohistochemistry of lysozyme in bats. 982 87

Immediate-type allergic reactions to latex products made from natural rubber are called latex allergy. One of the notable features of latex-allergic people is their cross-reactivity to various vegetable foods and pollen. The structurally similar proteins which most kinds of plants potentially induce must be responsible for these cross-reactions. However, the taxonomical dissimilarity among the causative plants has kept us from concrete explanations of such cross-reactive allergens. We have speculated that plant defense-related proteins are a possible cause of the latex allergy. The well-known serologic relationships and sequence similarities of these ubiquitous plant proteins can explain the cross-reactivity without difficulty. Rubber trees cultured in plantation farms are repeatedly tapped and treated with phytohormones. These stresses would result in the significant induction of defense-related proteins. Indeed, we were able to detect defense-related enzymes in latex extracts. Moreover, three hydrolytic enzymes (beta-1,3-glucanase, chitinase/lysozyme, and carboxylesterase) that are very likely to take a defensive role were specifically recognized by the IgE antibodies of latex-allergic people and atopic patients. These experimental results strongly support our hypothesis. Because of their conserved structures, defense-related proteins should form a family of plant pan-allergens.
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PMID:[Plant defense-related proteins as latex allergens]. 1009 12

When a Monascus isolate, a producer of Monascus pigments, was cocultured with either Saccharomyces cerevisiae or Aspergillus oryzae in a solid sucrose medium, there were significant morphological changes in Monascus culture. Cocultures exhibited cell mass increases of 2 times and pigment yield increases of 30 to 40 times compared to monocultures of Monascus. However, enhanced cell growth, an increase in pigment production, and morphological change did not occur in coculture with Bacillus cereus. Saccharomyces cerevisiae was more effective at enhancing pigment production than Asp. oryzae. Enhanced cell growth and increased pigment production occurred only in conjunction with morphological changes. Culture filtrates of S. cerevisiae were also effective in inducing morphology change in Monascus, similar to culture broths of S. cerevisiae. The hydrolytic enzymes produced by S. cerevisiae, such as amylase, and chitinase, are thought to be the effectors. The commercial enzymes alpha-amylase and protease from Asp. oryzae both caused a morphological change in Monascus and were effective in enhancing pigment production. However, lysozyme, alpha-amylase and protease from Bacillus species, protease from Staphylococcus, and chitinase from Streptomyces were not effective. The hydrolytic enzymes which cause a morphological change of Monascus culture and enhancement of pigment production are thought to be capable of degrading Monascus cell walls. An approximate 10-fold increase in pigment production was observed in liquid cocultures with S. cerevisiae. Copyright 1998 John Wiley & Sons, Inc.
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PMID:Morphological change and enhanced pigment production of monascus when cocultured with saccharomyces cerevisiae or aspergillus oryzae 1009 74

Intravenous infection of guinea pigs with the fungus Aspergillus fumigatus resulted in increased levels of chitinase in serum and tissues of the animals. The molecular properties of the enzyme were demonstrated to be different from those of the fungal chitinase, but also from guinea pig lysozyme and beta-N-acetylhexosaminidase. Bio-Gel P-100 gel filtration showed that in liver, spleen, heart and lung tissue of control animals there were two molecular mass forms present with apparent molecular masses of 35 kDa and 15 kDa. In brain and serum, only the 35 kDa form was detectable. Kidney showed only the 15 kDa form. Upon infection the 35 kDa form appeared in kidney and increased in the other tissues. When a less pathogenic form of the fungus was used the 35 kDa form remained absent in kidney. In contrast to human serum chitinase, the enzyme from guinea pig serum and tissues did bind to concanavalin A-Sepharose. This was the case for both molecular mass forms. The mode of cleavage of the substrate 4-methylumbelliferyl-tri-N-acetylchitotrioside (MU-[GlcNAc]3, where GlcNAc is N-acetylglucosamine) by the two forms of the enzyme was the same: both [GlcNAc]2 and [GlcNAc]3 were released. The chitinase activity levels in the control tissues showed a large variation in this order: spleen > lung, kidney > liver > heart > brain. The fact that spleen showed the highest chitinase level is in agreement with its major role as a lymphoid organ in cases of systemic infections. The relative increases upon infection were the highest for the tissues that showed low control values.
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PMID:Distribution of chitinase in guinea pig tissues and increases in levels of this enzyme after systemic infection with Aspergillus fumigatus. 1020 6

In recent studies the existence of a chitinase in various mammals, like man, was described. The aim of the present study was to find out whether salivas of periodontally healthy and inflamed humans also contain chitinase activity. Chitinase activity, assayed with the substrate 4-methylumbelliferyl-beta-D-N,N',N"-triacetylchitotrioside, was shown to be present in human whole saliva, with an activity level and apparent molecular mass (35 kDa) that were comparable with those of the human serum enzyme. Both lysozyme and beta-N-acetylhexosaminidase could be separated from chitinase by means of Bio-Gel P-100 gel filtration chromatography. The enzyme was also present in glandular saliva of parotid, palatine, submandibular and sublingual glands. The chitinase activity was not of oral epithelial, bacterial or plaque bacterial origin and was not correlated with the activity of salivary amylase. A comparative study of whole salivas of periodontally healthy controls and gingivitis and periodontitis subjects showed that only in the case of periodontitis there was a significant increase of the specific chitinase activity. The latter enzyme showed a gel filtration pattern that was comparable with that of the enzyme from controls. The measured albumin levels in saliva and the absence of correlation between the chitinase activity levels in plasma and saliva from periodontitis patients indicated that the (increased) chitinase activities did not originate from blood leakage to the oral cavity.
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PMID:Chitinase in whole and glandular human salivas and in whole saliva of patients with periodontal inflammation. 1051 97

The most comprehensive studies on a plant lysozyme (EC 3.2.1.17) are those on the enzyme from papaya (Carica papaya) latex, published in 1967 and 1969. However, the N-terminal amino acid sequence of five amino acid sequence of this enzyme, determined by manual Edman degradation, did not allow assignment to any of the much later-classified families of glycosyl hydrolases. N-Terminal sequence analysis of 22 residues of papaya lysozyme now shows unambiguously that the enzyme belongs to the family 19 chitinases. It has properties similar to those of basic class I chitinases with lysozyme activity, such as cleavage specificity at the C-1 of N-acetylmuramic acid with inversion of configuration, but as it lacks an N-terminal hevein domain, it should be classified as a class II chitinase.
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PMID:Papaya (Carica papaya) lysozyme is a member of the family 19 (basic, class II) chitinases. 1059 85

The chromosome of Escherichia coli K-12 contains a putative gene, yheB (chiA), at centisome 74.7, whose product shows sequence similarity with chitinases of bacterial and viral origin. We cloned the chiA (yheB) gene and demonstrated that it codes for a 94.5 kDa periplasmic protein with endochitinase/lysozyme activity. Under standard laboratory growth conditions, chiA expression is very low, as shown by the Lac- phenotype of a chiA transcriptional fusion to a promoterless lacZ reporter. To identify factors that control chitinase gene expression, we generated random Tn10 insertions in the chromosome of the fusion-containing strain, selecting for a Lac+ phenotype. The majority of the mutations that caused a Lac+ phenotype mapped to the hns gene, encoding the nucleoid-structuring protein H-NS. Transcription of chiA in vivo is driven by a single sigma70 promoter and is derepressed in an hns mutant. Using a competitive gel retardation assay, we demonstrated that H-NS binds directly and with high affinity to the chiA promoter region. In addition to hns, other E. coli mutations causing defects in global regulatory proteins, such as fis, crp or stpA in combination with hns, increased chiA expression to different extents, as did decreasing the growth temperature from 37 degrees C to 30 degrees C. A possible physiological function of ChiA (YheB) endochitinase in E. coli K-12 is discussed.
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PMID:The ChiA (YheB) protein of Escherichia coli K-12 is an endochitinase whose gene is negatively controlled by the nucleoid-structuring protein H-NS. 1076 Jan 50

In addition to chitinase/lysozyme, Pseudomonas aeruginosa K-187 also produced a protease useful for the deproteinization of shrimp and crab shell wastes. The optimal culture conditions for P. aeruginosa K-187 to attain the highest protease activity were investigated and discussed. The highest protease activity was as high as 21.2 U/ml, 10-fold that (2.2 U/ml) obtained prior to optimization. The protease of P. aeruginosa K-187, produced under the optimal culture conditions, was tested for crustacean waste deproteinization. The percent of protein removal for shrimp and crab shell powder (SCSP) after 7-day incubation was 72%, while that of natural shrimp shell (NSS) and acid-treated SCSP was 78% and 45%, respectively. In contrast, with the protease produced under pre-optimization conditions, the percent of protein removal for SCSP, NSS, and acid-treated SCSP was 48%, 55%, and 40%, respectively. For comparison, three other protease-producing microbes were tested for crustacean waste deproteinization. However, they were shown to be less efficient in deproteinization than P. aeruginosa K-187. The crude protease produced by P. aeruginosa K-187 can be covalently immobilized on a reversibly soluble polymeric support (hydroxypropyl methycellulose acetate succinate). The immobilized enzyme was soluble above pH 5.5 but insoluble below pH 4.5. Immobilization efficiency was 82%. The immobilized enzyme was stable between pH 6 and 9 and at temperatures below 60 degrees C. The optimum pH and temperature for the immobilized enzyme was pH 8 and 50 degrees C. The half-life of the immobilized enzyme was 12 days, longer than that of free protease (8 days). The utilization of the immobilized enzyme for the deproteinization of SCSP has resulted in a 67% protein removal. By contrast, SCSP protein removal by using free enzymes was 72%. The protease was further purified and characterized. The purification steps included ammonium sulfate precipitation, DEAE-Sepharose CL-6B ion-exchange chromatography, and Sephacryl S-200 gel-permeation chromatography. The enzyme had a molecular weight estimated to be 58.8 kDa by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme was active from pH 7 to 9 and its optimal pH was 8.
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PMID:Protease produced by Pseudomonas aeruginosa K-187 and its application in the deproteinization of shrimp and crab shell wastes. 1086 95

The structure of jack bean chitinase was solved at 1.8 A resolution by molecular replacement. It is an alpha-helical protein with three disulfide bridges. The active site is related in structure to animal and viral lysozymes. However, unlike in lysozyme, the architecture of the active site suggests a single-step cleavage. According to this mechanism, Glu68 is the proton donor and Glu90 assists in the reaction by moving towards the substrate and recruiting a water molecule that acts as the nucleophile. In this model, a water molecule was found in contact with Glu90 O(epsilon1) and Thr119 O(gamma) at a distance of 3.0 and 2.8 A, respectively. The model is in accordance with the observed inversion mechanism.
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PMID:Structure of jack bean chitinase. 1095 28

Most studies on chitinase activity in lizards have been concerned with Palaearctic (European) and Laurasian (Middle Eastern and Asian) taxa. Several genera of Old World lizards, Anguis, Uromastix, Chamaeleo and Lacerta, have been shown to possess chitinolytic activity. To date, only one New World lizard, Anolis carolinensis, has been reported to exhibit chitinolytic activity. In the present study, chitinase activity was characterized in a second New World taxon, Sceloporus undulatus garmani, a New World, phrynosomatid lizard. Chitinolytic activity was measured by incubating tissue extracts with a radioactive chitin substrate, acetyl-[H3]chitin and determining acid soluble radioactivity as an estimate for chitin hydrolysis. Chitinolytic activity was present in stomach, small intestine and pancreas extracts, with the stomach and pancreas having the highest specific activities. Chitinolytic activity was higher at pH 4.5 than at pH 7.5. The stomach chitinase is immunologically similar to the gastric chitinase previously described for rainbow trout. Western blot analysis showed anti-chitinase cross-reactivity in the extracts of the stomach, but no cross-reactivity in the pancreatic or intestinal extracts, suggesting different isoforms of chitinase. There was no detected lysozyme activity (less than 0.01 mg/ml lysozyme) present in the extracts of the stomach, small intestine and pancreas. The localization of chitinolytic activity in S. u. garmani is in agreement with earlier reptilian reports on the distribution of chitinase.
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PMID:Characterization of gastrointestinal chitinase in the lizard Sceloporus undulatus garmani (Reptilia: Phrynosomatidae). 1129 Apr 49


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