Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subcloning analysis of a cloned DNA fragment from Bacillus circulans containing the chitinase gene Chi1 showed that the chitinase gene lies on a 1.7kb PstI-StyI fragment. The chitinase gene could be expressed in Escherichia coli strains JM107, DH5alpha, XL1-blue and TG-1 with various efficiencies. The expression level of chitinase gene was highest in JM107, which was almost the same as that in B. circulans C-2. The molecular weight of extracellular chitinase was 66 kD by SDS-PAGE analysis. Cell location determination of the expressed chitinase showed that the enzyme existed not only in cell periplasm and cytoplasm, but also in extracellular broth. When the expression of the enzyme was optimal, the distribution of enzyme activity in extracellular broth, periplasm and cytoplasm was 35.8%, 32.1% and 32.9%, respectively.
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PMID:High Efficient Expression in Escherichia coli of Chitinase Gene Cloned from Bacillus circulans C-2. 1216 36

An extracellular chitinase secreted by Bacillus brevis was purified to homogeneity by a combination of ammonium sulfate precipitation, Phenyl-Sepharose hydrophobic-interaction chromatography and DEAE anion-exchange chromatography. On SDS-polyacrylamide gel electrophoresis analysis, the purified enzyme showed a mass of 85 kD even in the presence of beta mercaptoethanol, but shifted to 48 kD when heated in boiling water or treated with 8 mol/L urea at 50 degrees for 10 min. The depolymerization of subunits was accompanied with the loss of chitinase activity, and removing denaturing factors by dialysis could restore the dimer structure and enzymatic activity. The enzyme had an isoelectric point of 5.5 and an optimal temperature of 60 degrees, and was most active at pH 8.0. The enzymatic activity was stable at pH 6-10, and inhibited by Ag(+). Ten N-terminal amino acids were determined to be AVSNSKIIGY, demonstrating that the purified enzyme was a novel one. The hydrolysis pattern of the purified enzyme indicated that the chitinase was an endochitinase. The extraordinary thermo-stability and high resistance to proteolysis provide the enzyme with a good prospect to be used as a new tool for biocontrol.
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PMID:Purification and characterization of a novel chitinase from Bacillus brevis. 1241 8

Measurement of the hydrolysis of specific fluorogenic substrates by spectrophotometry as well as the substrate activity-SDS-PAGE gel analysis of the chitinolytic activity in Aedes aegypti guts showed that both chitinase and beta-N-acetylglucosaminidase are present and physiologically active. Both enzymes were present even in guts from unfed insects, but the activities increased rapidly after feeding on blood or an artificial protein-free diet. Chitinase activity was predominantly of the 'endo'-type, reaching its maximum activity at 36 h and then declining to very low levels after the degradation of the peritrophic matrix (PM). 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. Hydrolysis of a chitinase-specific substrate by chitinolytic activities in the mosquito guts was inhibited by allosamidin, a potent chitinase inhibitor. Allosamidin treatment led to the formation of an atypical thick PM, while the addition of exogenous chitinase completely blocked its formation. This chitinolytic system appears to operate both on the formation and degradation of the PM. Since the PM is involved in pathogen invasion, these results are important in facilitating a search for mechanisms that can block pathogen development in the mosquito vector.
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PMID:Presence of chitinase and beta-N-acetylglucosaminidase in the Aedes aegypti. a chitinolytic system involving peritrophic matrix formation and degradation. 1242 24

The secretory cells lining the lumen of the mammalian oviduct synthesize and secrete high molecular weight glycoprotein (OGP). Molecular cDNA cloning of most of the mammalian OGP has been accomplished. The nucleotide and deduced amino acid sequences show a remarkable homology across species and also to chitinase protein. Even though OGP has been shown to interact with gametes and the early embryo, the protein's direct function has not yet been established. A prerequisite for such studies is the availability of well-characterized protein in bulk. We used recombinant DNA technology to obtain OGP (rOGP). An authentic partial cDNA clone encoding bonnet monkey (Macaca radiata) OGP (accession number AF132 215) was recloned into expression vector pET20b. Overexpression of the protein could be demonstrated after induction with isopropylthio-beta-galactopyranoside. Recombinant protein was purified by gel filtration of Escherichia coli lysate through Sephadex G75. The protein migrated with a molecular weight of approximately 14 kDa on SDS-PAGE. The molecular weight as assessed by matrix-assisted laser adsorption time-of-flight was 14 439 daltons. With Western blot procedures the protein could be immunostained with antibodies to human OGP, baboon OGP, and antipeptide antibodies generated against a well-conserved region of mammalian OGP. The monospecificity of rabbit antibodies generated against rOGP was established by its ability to immunostain human OGP (100-110 kDa) isolated from hydrosalpinx by Western blot analysis, and the antibody immunostained epithelial cells that secrete OGP in human fallopian tubes. OGP binding sites on the head and tail region of monkey sperm could be demonstrated by using antibody against rOGP.
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PMID:Overexpression of monkey oviductal protein: purification and characterization of recombinant protein and its antibodies. 1244 68

A bacterium producing chitinase was isolated from the dead body of Gymephorap ruoergensis. A chitinase was isolated from the culture of E. aerogenes and purified by means of ammonium sulfate precipitation, DEAE-cellulose column chromatography, and Sephadex G-100 column gel filtration. The purified chitinase showed homogeneity on the native polyacrylamide gel electrophoresis. Its molecular weight was estimated to be about 42.5 kD by SDS-PAGE. The optimum pH and temperature for hydrolysis of chitin were 6.0 and 55 degrees C respectively. Michaelis constant was 2.88 mg/mL. Different metal ions showed different effects on the chitinase activity, The chitinase activity was enhanced by Zn2+, Ba2+, Ca2+, Mn2+ and was strongly inhibited by Hg2+, Co2+, Mg2+.
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PMID:[Purification and properties of chitinase from Enterobacter aerogenes]. 1254 94

A 1.8 kb HinfI fragment carrying the chitinase gene (chiA) from Serratia marcescens was cloned into the expression vector pKK223-3 and the plasmid pMC71A, yielded the plasmid pKChiA and the plasmid pMChiA respectively. Both plasmid pKChiA and plasmid pMChiA were used to transform to the Enterobacter cloacae strain E26 and the Klebsiella oxytoca strain NG13, two nitrogen-fixing bacteria associated with rice root. The chiA gene could be highly expressed in the ChiA+ transformants of the strain E26 or the strain NG13. Cell location determination of the expressed chitinase showed that the enzyme existed not only in cell periplasm and cytoplasm, but also in extracellular broth. When the cultures were in the aftor logarithmic growthe phase, the distribution of the enzyme activity in extracellular broth, periplasm and cytoplasm were 23%-28%, 45%-51% and 21%-32%, respectively. The molecular weight of chitinase expressed in the ChiA+ transformants was 58 kD by SDS-PAGE analysis. The stability of the plasmid pMChiA in the transformants was better than that of the plasmid pKChiA.
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PMID:[Expression of the chiA gene from Serratia marcescens in both strain E26 and strain NG13, nitrogen-fixing bacteria associated with rice root]. 1255 24

A new chitinase (1,4-beta-D-N-acetyl-glucosaminidase, EC 3.2.1.14) was detected and purified to homogeneity in its native form from the chitinolytic enzyme system of the extremely thermophilic archaeon Thermococcus chitonophagus. This is the first nonrecombinant chitinase purified and characterized from archaea and also constitutes the first case of a membrane-associated chitinase isolated from archaea. The enzyme is a monomer with an apparent molecular weight of 70 kDa [therefore named chitinase 70 (Chi70)] and pI of 5.9; it is hydrophobic and appears to be associated with the outer side of the cell membrane. Chi70 is optimally active at 70 degrees C and pH 7.0 and exhibits remarkable thermostability, maintaining 50% activity even after 1 h at 120 degrees C, and therefore the enzyme is the most thermostable chitinase so far isolated. The enzyme was not inhibited by allosamidin, the natural inhibitor of chitinolytic activity, and was also resistant to denaturation by urea and SDS. On the other hand, guanidine hydrochloride significantly reduced enzymatic activity, indicating that, apart from the hydrophobic interactions, ion pairs located on the surface of the protein could be playing an important role in maintaining the protein's fold and enzyme activity. Chi70 showed broad substrate specificity for several chitinous substrates and derivatives. The lowest K(m) and highest K(cat) values were found for pNP(NAG)(2) as substrate and were determined to be 0.14 mM and 23 min(-1), respectively. The hydrolysis pattern was similar for oligomers and polymers, with N, N'-diacetylchitobiose [(NAG)(2)] being the final, major hydrolysis product. Chi70 was classified as an endochitinase due to its ability to release chitobiose from colloidal chitin. Additionally, the enzyme presented considerable cellulolytic activity. Analysis of the NH(2)-terminal amino acid sequence showed no detectable homology with other known sequences, suggesting that Chi70 is a new protein.
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PMID:Purification and characterization of a new hyperthermostable, allosamidin-insensitive and denaturation-resistant chitinase from the hyperthermophilic archaeon Thermococcus chitonophagus. 1257 79

Protein was extracted from root bark of 11- and 25-year-old interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees that were naturally infected with Armillaria ostoyae (Romagnesi) Herink. The proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Root bark tissue adjacent to infected areas had a significantly higher protein concentration than healthy tissue (P < 0.05), whereas the protein concentration of infected tissue was consistently lower (P < 0.05) than that of healthy tissue. The SDS-PAGE profiles of healthy, infected, and adjacent-to-infected root bark tissues revealed significant differences in concentrations of a 29.3-kDa protein. The N-terminal amino acid sequence of the 29.3-kDa protein displayed significant homology (P = 0.013) to a basic endochitinase. Use of a polyclonal antibody raised against the 29.3-kDa putative endochitinase-like protein (ECP) indicated differences in the quantities of ECP in healthy roots compared with roots infected with A. ostoyae in 11- and 25-year-old interior Douglas-fir trees. The antibody was also used to screen for the presence of the 29.3-kDa protein in roots of 24-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) trees that were artificially inoculated with and colonized by Phellinus weirii (Murr.) Gilbn. The amount of ECP was elevated in root bark of coastal Douglas-fir in response to P. weirii infection, although in lower quantities relative to those found in the A. ostoyae-interior Douglas-fir pathosystem. The sequence homology of the ECP with a basic chitinase, together with its increased synthesis in response to two fungal pathogens, indicate a possible role for this protein in the defense of Douglas-fir against fungal pathogens.
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PMID:Detection of a chitinase-like protein in the roots of Douglas-fir trees infected with Armillaria ostoyae and Phellinus weirii. 1265 29

Extracellular chitinase from Alcaligenes xylosoxydans was purified to electrophoretic homogeneity using affinity and gel filtration chromatography. The molecular mass of chitinase was estimated to be 45 kDa and 44 kDa by SDS-PAGE and gel-filtration, respectively. The enzyme was optimally active at 50 degrees C (over 30 min) and pH 5. Activity staining after PAGE showed a single band. The Km for chitin was 3 g l-1. Cu2+ and Na+ at 5 mM inhibited chitinase activity to 25% while Ca2+, Mg2+ and Ba2+ had no effect at the same concentration. The purified enzyme degraded mycelia of Aspergillus niger.
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PMID:Purification and characterization of chitinase from Alcaligenes xylosoxydans. 1288 72

KA-prep, a culture filtrate of Bacillus circulans KA-304 grown on a cell-wall preparation (CWP) of Schizophyllum commune, has been reported to have an activity to form protoplasts from S. commune mycelia. The SDS-polyacrylamide gel electrophoreses described here demonstrated that a specific proteinous component (molecular weight: 150,000) occurred in KA-prep. The protein (P150T) was also formed in culture filtrates with CWP of several basidiomycetes, which could release the protoplasts, suggesting that the component was an indispensable factor for protoplast formation. P150T, isolated from an ammonium sulfate fraction of KA-prep (0-30% saturation), did not have any protoplast-forming activity. Results were obtained indicating that P150T participates in protoplast formation together with chitinase(s) and beta-glucanase(s) in KA-prep. The N-terminal amino acid sequence indicated an analogy of P150T to mutanase (alpha-1,3-glucanase) from Bacillus sp. RM1, and actually P150T hydrolyzed mutan as well as S-(alpha-1,3) glucan from S. commune.
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PMID:Occurrence of a specific protein in basidiomycete-lytic enzyme preparation produced by Bacillus circulans KA-304 inductively with a cell-wall preparation of Schizophyllum commune. 1451 84


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