Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.10.3.2 (laccase)
4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organism Trichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase, and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum.
...
PMID:Changes in selected enzyme activities during growth of pure and mixed cultures of the white-rot decay fungus Trametes versicolor and the potential biocontrol fungus Trichoderma harzianum. 161 57

A multicomponent protein complex containing manganese (II)-dependent peroxidase, laccase and beta-glucosidase was isolated from culture extracts of the white rot basidiomycete Lentinula edodes. This protein complex showed a single protein band on native polyacrylamide gel electrophoresis (PAGE). On sodium dodecyl sulfate (SDS)-PAGE, however, it displayed three major bands and several additional minor bands ranging in size from 60 kDa to 180 kDa, suggesting it being a complex of six to eight different proteins. The molecular mass of this complex was estimated to be approximately 660 kDa from the elution position of gel filtration. This enzyme complex was effective in transforming environmentally persistent xenobiotics, pentachlorophenol and 2,5-dichlorophenol.
...
PMID:Lentinula edodes produces a multicomponent protein complex containing manganese (II)-dependent peroxidase, laccase and beta-glucosidase. 1142 71

Activity of a number of enzymes related to lignin formation was measured in a Picea abies (L) Karsten suspension culture that is able to produce native-like lignin into the nutrient medium. This cell culture is an attractive model for studying lignin formation, as the process takes place independently of the complex macromolecular matrix of the native apoplast. Suspension culture proteins were fractionated into soluble cellular proteins, ionically and covalently bound cell wall proteins and nutrient medium proteins. The nutrient medium contained up to 5.3% of total coniferyl alcohol peroxidase (EC 1.11.1.7) activity and a significant NADH oxidase activity that is suggested to be responsible for hydrogen peroxide (H2O2) production. There also existed some malate dehydrogenase (EC 1.1.1.37) activity in the apoplast of suspension culture cells (in ionically and covalently bound cell wall protein fractions), possibly for the regeneration of NADH that is needed for peroxidase-catalysed H2O2 production. However, there is no proof of the existence of NADH in the apoplast. Nutrient medium peroxidases could be classified into acidic, slightly basic and highly basic isoenzyme groups by isoelectric focusing. Only acidic peroxidases were found in the covalently bound cell wall protein fraction. Several peroxidase isoenzymes across the whole pI range were detected in the protein fraction ionically bound to cell walls and in the soluble cellular protein fraction. One laccase-like isoenzyme with pI of approximately 8.5 was found in the nutrient medium that was able to form dehydrogenation polymer from coniferyl alcohol in the absence of H2O2. The total activity of this oxidase towards coniferyl alcohol was, however, several orders of magnitude smaller than that of peroxidases in vitro. According to 2D 1H-13C correlation NMR spectra, most of the abundant structural units of native lignin and released suspension culture lignin are present in the oxidase produced dehydrogenation polymer but in somewhat different amounts compared to peroxidase derived synthetic lignin preparations. A coniferin beta-glucosidase (EC 3.2.1.21) was observed to be secreted into the culture medium.
...
PMID:Lignification related enzymes in Picea abies suspension cultures. 1206 Feb 56

The activities of carboxymethylcellulase and xylanase in the higher basidial fungus Cerrena unicolor grown in avicel-containing medium reached 1.95 and 1.50 units per mg protein, respectively, whereas in mannitol-containing medium they ranged from 0.02 to 0.05 units per mg protein. The activity of fungal beta-glucosidase depended on the carbon source in the culture medium and ranged from 2.1 units per mg protein in the presence of mannitol to 17.3 units per mg protein in the presence of avicel. In contrast to polysaccharides, easily metabolizable substrates (cellobiose, mannitol, and glucose) provided the highest rates of secretion of laccase (52.7-123.5 ncat per mg protein) and ligninase (22-106 units per mg protein). The addition of tangerine pomace, a substrate enriched with aromatic compounds, to the culture medium caused an increase in the rate of bio-synthesis of laccase and ligninase to 862 ncat per ml and 557 units per ml, respectively. Aromatic compounds such as p-xylidine and veratric aldehyde increased the laccase activity of C. unicolor IBB 62 from 7.9 to 23.6 and 18.3 ncat per mg protein, respectively. Veratryl alcohol caused a sevenfold increase in the activity of Mn-dependent peroxidase in the culture medium.
...
PMID:[Dependence of activities of polysaccharide hydrolases and oxidases from Cerrena unicolor on the source of carbon and aromatic acids in culture media]. 1206 74

Most of white-rot fungi, such as Phanerochaete chrysosporium, can cause severe concomitant cellulose degradation during biodegradation of lignocellulose. Panus conchatus, a white-rot fungus, can cause efficient delignification of straw with only limited concomitant cellulose degradation. The results in comparison of lignocellulolytic enzyme profiles secreted by P. conchatus and P. chrysosporium during solid state cultures have shown that laccase and Mn-dependent peroxidase are main lignin-degrading enzymes of these two fungi respectively; high activities of xylanase are secreted by both fungi; and much lower activities of cellulases i.e. endo-glucanase, avicelase and cellobiase, especially endo-glucanase, are produced by P. conchatus during the whole cultures. The results further confirm that Panus conchatus has ability of strong selective delignification of lignocellulose.
...
PMID:[Comparison of lignocellulolytic enzyme profiles secreted by Panus conchatus and Phanerochaete chrysosporium during solid state cultures]. 1255 16

Activities of cellulolytic and hemicellulolytic enzymes endo-1,4-beta-glucanase, exo-1,4-beta-glucanase, 1,4-beta-glucosidase, endo-1,4-beta-xylanase, 1,4-beta-xylosidase and 1,4-beta-mannosidase and ligninolytic enzymes Mn-peroxidase and laccase were detected during the growth of the white-rot fungus Pleurotus ostreatus on wheat straw in the presence and absence of cadmium. The loss of substrate dry weight and Mn-peroxidase activity decreased with increasing Cd concentration, whereas the activities of endo-1,4-beta-glucanase, 1,4-beta-glucosidase and laccase were highly increased in the presence of metal. The onset of hemicellulose-degrading enzyme activity was delayed in the presence of cadmium. The degradation of a model synthetic dye Poly B-411 did not correspond to the activities of ligninolytic enzymes. This is the first report about 1,4-beta-mannosidase in P. ostreatus.
...
PMID:Lignocellulose degradation by Pleurotus ostreatus in the presence of cadmium. 1267 Jun 86

The effect of the addition of the nonionic surfactant tributylphenyltetraethoxylate to culture media on pH and extracellular protein content, and on production of beta-glucosidase, xylanase, laccase, and manganese-dependent and -independent peroxidases by the edible fungus Pleurotus ostreatus was determined. The relationship between fermentation parameters and concentration of surfactant was assessed by multiple linear regression analysis, and the similarities and differences among the fermentation parameters were elucidated by principal component analysis. Calculations proved that except for xylanase all other cultivation parameters were significantly influenced by the surfactant, with the effect higher at higher surfactant concentrations. Surfactant increased the production of beta-glucosidase and inhibited laccase and manganese-dependent and -independent peroxidase activities.
...
PMID:Effect of tributylphenyltetraethoxylate on enzyme production of Pleurotus ostreatus. 1290 30

Twenty-six species of aquatic hyphomycetes were isolated from woody sources (unidentified wood segments, leaf skeletons and neck of leaves and bark) in the North River Nile (Delta region). Alatospora acuminata, Anguillospora crassa, Flagellaspora penicillioides, Lunulospra curvula, Tetracladium marchalianum and Triscelophorus monosporus were the most common species. Temperature was the highest physico-chemical parameter affecting the aquatic hyphomycetes occurrence. Twelve species of hyphomycetes, isolated from woody substrates, were screened for their ability to produce extracellular lignocellulolytic enzymes on solid media. The enzymes tested included: endoglucanase, endoxylanase, beta-glucosidase, laccase, peroxidase, polyphenoloxidase, tyrosinase and beta-xylosidase. Three species, A. acuminata, F. penicillioides, T. monosporus, were positive for all tested enzymes. Also, A. longissima was positive for all enzymes except lignin-peroxidase. The ability to produce cellulase was 100% for all species while only, four species were positive for lignin-peroxidase. The ability of the species to produce other lignocellulotic enzyme ranged from 50% to 83%. Freshwater hyphomycetes have been shown to produce a rich array of enzymes able to degrade the polysaccharides of plant debris.
...
PMID:Lignocellulolytic enzyme production by aquatic hyphomycetes species isolated from the Nile's delta region. 1518 Jan 56

In this study we examined the extracellular enzymatic activity of two white rot fungi (Phanerochaete chrysosporium and Trametes versicolor) in a soil extract broth in relation to differential degradation of a mixture of different concentrations (0-30 p.p.m.) of simazine, dieldrin and trifluralin under different osmotic stress (-0.7 and -2.8 MPa) and quantified enzyme production, relevant to P and N release (phosphomonoesterase, protease), carbon cycling (beta-glucosidase, cellulase) and laccase activity, involved in lignin degradation. Our results suggest that T. versicolor and P. chrysosporium have the ability to degrade different groups of pesticides, supported by the capacity for expression of a range of extracellular enzymes at both -0.7 and -2.8 MPa water potential. Phanerochaete chrysosporium was able to degrade this mixture of pesticides independently of laccase activity. In soil extract, T. versicolor was able to produce the same range of enzymes as P. chrysoporium plus laccase, even in the presence of 30 p.p.m. of the pesticide mixture. Complete degradation of dieldrin and trifluralin was observed, while about 80% of the simazine was degraded regardless of osmotic stress treatment in a nutritionally poor soil extract broth. The capacity of tolerance and degradation of high concentrations of mixtures of pesticides and production of a range of enzymes, even under osmotic stress, suggest potential bioremediation applications.
...
PMID:Enzymatic activity, osmotic stress and degradation of pesticide mixtures in soil extract liquid broth inoculated with Phanerochaete chrysosporium and Trametes versicolor. 1568 95

Pleurotus ostreatus produces the cellulolytic and hemicellulolytic enzymes endo-1,4-beta-glucanase, exo-1,4-beta-glucanase, 1,4-beta-glucosidase, endo-1,4-beta-xylanase, 1,4-beta-xylosidase, endo-1,4-beta-mannanase and 1,4-beta-mannosidase and ligninolytic enzymes Mn-peroxidase and laccase during growth on wheat straw in the presence and absence of Cu, Mn, Pb, and Zn. This is the first report concerning endo-1,4-beta-mannanase in P. ostreatus. Although the concentrations of trace metals in wheat straw ranged from units to tens of microg g(-1), only 3-6% (Fe, Pb) or 30-45% (Cu, Mn, Zn) of the total amount was extractable and available for the fungus. The substrate colonization rate was only decreased by high concentrations of Cu and Zn; the loss of dry mass differed among treatments in the initial phase of fungal growth, and at the end of the experiment (day 98) it was significantly lower in metal-containing treatments (63-66%) than in the control (70%). The cellulolytic and hemicellulolytic enzyme were prone to a metal effect except for the increase in endo-1,4-beta-glucanase and 1,4-beta-glucosidase in the presence of Zn. Laccase activity was increased by all tested metals, and unlike other white-rot fungi, Mn-peroxidase levels were low in the presence of manganese.
...
PMID:Degradation of lignocellulose by Pleurotus ostreatus in the presence of copper, manganese, lead and zinc. 1592 94


1 2 3 Next >>

---