Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.2 (laccase)
 4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We compared the gene expression patterns of Lentinula edodes fresh fruiting bodies and fruiting bodies 3 days after harvest, by suppression subtractive hybridization, to characterize the physiologic changes that occur after harvest, such as gill browning and cell wall lysis of the fruiting body, which are responsible for the loss of food quality and value. We found increase of transcription levels of several enzyme encoding genes, such as, two phenol oxidases encoding genes (tyr tyrosinase, lcc4 laccase), and several cell wall degradation-related enzyme-encoding genes, such as mixed-linked glucanase (mlg1), chitinases (chi1, chi2), chitin deacetylase (chd1), and chitosanase (cho1), after harvesting. We isolated a putative transcription factor-encoding gene (L. edodes exp1) with high similarity to exp1 from Coprinopsis cinerea, which is involved in autolysis of the cap during spore diffusion. Transcription of L. edodes exp1 increased post-harvest, which suggests that its target genes are up-regulated after harvesting. These enzymes and the transcription factor may be involved in L. edodes fruiting body senescence.
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PMID:Characterization of the post-harvest changes in gene transcription in the gill of the Lentinula edodes fruiting body. 1948 57

Novel aerobic, Gram-negative bacteria with DNA G+C contents below 50 mol% were isolated from the culturable microbiota associated with the Mediterranean seagrass Posidonia oceanica. 16S rRNA gene sequence analyses revealed that they belong to the genus Marinomonas. Strain IVIA-Po-186 is a strain of the species Marinomonas mediterranea, showing 99.77 % 16S rRNA gene sequence similarity with the type strain, MMB-1(T), and sharing all phenotypic characteristics studied. This is the first description of this species forming part of the microbiota of a marine plant. A second strain, designated IVIA-Po-101(T), was closely related to M. mediterranea based on phylogenetic studies. However, it differed in characteristics such as melanin synthesis and tyrosinase, laccase and antimicrobial activities. In addition, strain IVIA-Po-101(T) was auxotrophic and unable to use acetate. IVIA-Po-101(T) shared 97.86 % 16S rRNA gene sequence similarity with M. mediterranea MMB-1(T), but the level of DNA-DNA relatedness between the two strains was only 10.3 %. On the basis of these data, strain IVIA-Po-101(T) is considered to represent a novel species of the genus Marinomonas, for which the name Marinomonas balearica sp. nov. is proposed. The type strain is IVIA-Po-101(T) (=CECT 7378(T) =NCIMB 14432(T)). A third novel strain, IVIA-Po-185(T), was phylogenetically distant from all recognized Marinomonas species. It shared the highest 16S rRNA gene sequence similarity (97.4 %) with the type strain of Marinomonas pontica, but the level of DNA-DNA relatedness between the two strains was only 14.5 %. A differential chemotaxonomic marker of this strain in the genus Marinomonas is the presence of the fatty acid C(17 : 0) cyclo. Strain IVIA-Po-185(T) is thus considered to represent a second novel species of the genus, for which the name Marinomonas pollencensis sp. nov. is proposed. The type strain is IVIA-Po-185(T) (=CECT 7375(T) =NCIMB 14435(T)). An emended description of the genus Marinomonas is given based on the description of these two novel species, as well as other Marinomonas species described after the original description of the genus.
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PMID:Taxonomic study of Marinomonas strains isolated from the seagrass Posidonia oceanica, with descriptions of Marinomonas balearica sp. nov. and Marinomonas pollencensis sp. nov. 1964 36

The fungal pathogen Lecanicillium fungicola (formerly Verticillium fungicola) is responsible for severe losses worldwide in the mushroom (Agaricus bisporus) industry. Infected crops are characterised by masses of undifferentiated tissue (bubbles) growing in place of sporophores. The expression of three laccase genes (lcc1, lcc2 and lcc3), two tyrosinase genes (AbPPO1 and AbPPO2) and the hspA gene encoding a heat-shock protein known to be potentially associated with host-pathogen interaction was investigated in mycelial aggregates and during the development of healthy sporophores and bubbles of a susceptible cultivar. The lcc3, AbPPO2 and hspA genes were each expressed at different levels at the different stages of sporophore morphogenesis, whilst they showed a stable expression throughout bubble development. The transcript levels were similar in bubbles and at the first developmental stage of healthy fruiting bodies, both showing no tissue differentiation. These observations suggest that lcc3, AbPPO2 and hspA are associated with A. bisporus morphogenesis. Comparing the expression of the hspA gene in three susceptible and three tolerant strains showed that the latter displayed a higher level of transcript in the primordium, which is the stage receptive to the pathogen. The six strains exhibited a comparable expression in the vegetative mycelium, non-receptive to L. fungicola.
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PMID:Expression of phenol oxidase and heat-shock genes during the development of Agaricus bisporus fruiting bodies, healthy and infected by Lecanicillium fungicola. 1971 Oct 71

Copper (Cu) is an essential element for the physiological function of organisms. In basidiomycetes, Cu is necessary for the production of phenol oxidase enzymes such as laccase and tyrosinase. We isolated and characterized two genes, CcCTR1 and -2, from the model basidiomycete Coprinopsis cinerea. CcCTR1 and -2 showed similarity to the Cu transporter CTR1 in Saccharomyces cerevisiae. Both CcCTRs had a MLxxM motif that is conserved in other CTR homologs. The addition of Cu to a liquid culture of C. cinerea decreased the mRNA accumulation of CcCTR1 and -2. Heterologous expression of CcCTR1 in S. cerevisiae increased Cu sensitivity, suggesting that CcCTR1 is a Cu uptake transporter. Together, these results suggest that CcCTR1 plays an important role in Cu accumulation in C. cinerea.
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PMID:Identification and characterization of CcCTR1, a copper uptake transporter-like gene, in Coprinopsis cinerea. 1971 88

Phenoloxidases (POs) are a family of enzymes including tyrosinases, catecholases and laccases, which play an important role in immune defence mechanisms in various invertebrates. The aim of this study was to thoroughly identify the PO-like activity present in the hemolymph of the Pacific oyster Crassostrea gigas, by using different substrates (i.e. dopamine and p-phenylenediamine, PPD) and different PO inhibitors. In order to go deeper in this analysis, we considered separately plasma and hemocyte lysate supernatant (HLS). In crude plasma, oxygraphic assays confirmed the presence of true oxidase activities. Moreover, the involvement of peroxidase(s) was excluded. In contrast to other molluscs, no tyrosinase-like activity was detected. With dopamine as substrate, PO-like activity was inhibited by the PO inhibitors tropolone, phenylthiourea (PTU), salicylhydroxamic acid and diethyldithio-carbamic acid, by a specific inhibitor of tyrosinases and catecholases, i.e. 4-hexylresorcinol (4-HR), and by a specific inhibitor of laccases, i.e. cetyltrimethylammonium bromide (CTAB). With PPD as substrate, PO-like activity was inhibited by PTU and CTAB. In precipitated protein fractions from plasma, and with dopamine and PPD as substrates, PTU and 4-HR, and PTU and CTAB inhibited PO-like activity, respectively. In precipitated protein fractions from hemocyte lysate supernatant, PTU and CTAB inhibited PO-like activity, independently of the substrate. Taken together, these results suggest the presence of both catecholase- and laccase-like activities in plasma, and the presence of a laccase-like activity in HLS. To the best of our knowledge, this is the first time that a laccase-like activity is identified in a mollusc by using specific substrates and inhibitors for laccase, opening new perspectives for studying the implication of this enzyme in immune defence mechanisms of molluscs of high economic value such as C. gigas.
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PMID:First evidence of laccase activity in the Pacific oyster Crassostrea gigas. 2010 60

Crosslinking enzymes are frequently used in bioprocessing of dairy products. The aim of this study was to examine the effects of enzymatic crosslinking on IgE binding, allergenicity and digestion stability of beta-casein (CN). beta-CN was crosslinked by transglutaminase, tyrosinase, mushroom tyrosinase/caffeic acid and laccase/caffeic acid. The IgE binding to beta-CN was compared in vitro by CAP inhibition assay, ELISA inhibition as well as ex vivo by basophil activation assay. Crosslinked CNs were digested by simulated gastric fluid for 15 and 60 min and obtained digests analyzed for their ability to inhibit IgE binding by CAP inhibition assay and SDS-PAGE. The ability of crosslinked CNs to activate basophils was significantly reduced in seven patients in the case of CN crosslinked by laccase and moderately reduced in the case of tyrosinase/caffeic acid crosslinked CN (in two cow's milk allergy patients tested with different allergen concentrations). The response to various crosslinked CNs differed individually among patients' sera tested by ELISA inhibition assay. The presence of caffeic acid hampered digestion by pepsin, and this effect was most pronounced for the tyrosinase/caffeic acid crosslinked CN. The laccase/caffeic acid and mushroom tyrosinase/caffeic acid had the highest potential in mitigating IgE binding and allergenicity of the beta-CN out of all investigated enzymes. The presence of a small phenolic compound also increased digestion stability of beta-CN.
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PMID:Digestibility and allergenicity assessment of enzymatically crosslinked beta-casein. 2020 91

In vitro culture plants of Typhonium flagelliforme were found to decolorize a variety of dyes, including Malachite Green, Red HE 8B, Methyl Orange, Reactive Red 2, Direct Red 5B (DR5B), Red HE 7B, Golden Yellow HER, Patent Blue, and Brilliant Blue R (BBR), to varying extents within 4 days. The enzymatic analysis of plant roots of aseptically raised plantlets performed before and after degradation of the dye BBR by these plantlets showed a significant induction in the activities of peroxidase, laccase, tyrosinase, and 2,6-dichlorophenol-indophenol reductase, which indicated the involvement of these enzymes in the metabolism of the dye. Comparative study of the enzyme status of the plants Typhonium flagelliforme and Blumea malcolmii during the degradation of DR5B and BBR showed marked variations in the enzyme profile with respect to the use of different sources of the enzyme. Phytoremediation of BBR using Typhonium flagelliforme was confirmed with high performance liquid chromatography and Fourier transform infrared spectroscopy analysis performed before and after the degradation of the dye. One of the products of the metabolism of the dye was identified as 4-(4-ethylimino-cyclohexa-2,5-dienylidinemethyl)-phenylamine with the aid of gas chromatography-mass spectroscopy (GC-MS) analysis. Significant decrease in the American Dye Manufacturer's Institute, biological oxygen demand, and chemical oxygen demand values of synthetic mixture of textile dyes and industrial effluent confirmed the decolorization and detoxification. Phytotoxicity studies also revealed the nontoxic nature of the metabolites of BBR.
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PMID:Studies on phytoremediation potentiality of Typhonium flagelliforme for the degradation of Brilliant Blue R. 2043 82

1,2-dehydro-N-acetyldopamine (dehydro NADA) is an important catecholamine derivative formed during the sclerotization of insect cuticle. Earlier we have reported that tyrosinase-catalyzed oxidation of dehydro NADA produces a reactive quinone methide imine amide that forms adducts and cross-links through its side chain, thereby accounting for sclerotization reactions. Recently, laccase has also been identified as a key enzyme associated with sclerotization. Hence, we re-examined oxidation of dehydro NADA by tyrosinase and laccase using high performance liquid chromatography - tandem mass spectrometry. Tyrosinase-catalyzed oxidation of dehydro NADA not only generated dimers as reported earlier, but also generated significant amounts of oligomers. The course of laccase-catalyzed oxidation of dehydro NADA significantly differed from the tyrosinase reaction kinetically and mechanistically. Laccase failed to produce any detectable quinone or quinone methide as the primary two-electron oxidation product. Since laccases are known to generate primarily semiquinones as the initial products, lack of accumulation of two-electron oxidation products indicated that laccase reaction is primarily occurring via free radical coupling mechanism. Consistent with this proposal, laccase-catalyzed oxidation of dehydro NADA, resulted in the production of largely dimeric products and failed to produce any significant amount of oligomeric materials. These studies call for radical coupling as yet another major mechanism for sclerotization of insect cuticle.
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PMID:Reexamination of the mechanisms of oxidative transformation of the insect cuticular sclerotizing precursor, 1,2-dehydro-N-acetyldopamine. 2060 Aug 98

Laccases (EC 1.10.3.2) are versatile multi-copper oxidases so far found in higher plants, fungi, insects, prokaryotes and lichens. In the present study, the production of an extracellular laccase-like enzyme by the coccoid green soil alga Tetracystis aeria was investigated and the enzyme was partly characterized, thereby providing the first description of a laccase-like enzyme in soil algae. Enzyme production in algae cultures was considerably increased by addition of the fungal laccase inducer copper sulphate. Maximal enzyme production was observed during the stationary growth phase. Peroxidase or tyrosinase activity was not detected. The native enzyme exhibits an apparent molecular mass of about 212 kDa as observed with size exclusion chromatography and about 210-260 kDa as estimated by zymograms. The enzyme efficiently oxidizes 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 2,6-dimethoxyphenol (2,6-DMP), syringaldazine (SGZ) and the anthraquinone dye Acid Blue 62, while guaiacol and Remazol Brilliant Blue R are only poorly oxidized. The apparent kinetic parameters obtained for ABTS, 2,6-DMP and SGZ oxidation are within the range reported for fungal laccases. Oxidation of the phenolic substrate 2,6-DMP displays a remarkably high pH optimum (pH 8.0-8.5), which is interesting with respect to potential biotechnological applications.
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PMID:First description of a laccase-like enzyme in soil algae. 2062 67

Some Gram-negative bacteria express a novel enzyme with lysine-epsilon-oxidase (LOD) activity (EC 1.4.3.20). The oxidation of l-Lys generates, among other products, hydrogen peroxide, which confers antimicrobial properties to this kind of enzyme and has been shown to be involved in cell death during biofilm development and differentiation. In addition to LOD, the melanogenic marine bacterium Marinomonas mediterranea, which forms part of the microbiota of the marine plant Posidonia oceanica, expresses two other oxidases of biotechnological interest, a multicopper oxidase, PpoA, with laccase activity and a tyrosinase named PpoB, which is responsible for melanin synthesis. By using both lacZ fusions with the lodAB promoter and quantitative reverse transcription-PCR (qRT-PCR), this study shows that the hybrid sensor histidine kinase PpoS regulates LOD activity at the transcriptional level. Although PpoS also regulates PpoA and PpoB, in this case, the regulatory effect cannot be attributed only to a transcriptional regulation. Further studies indicate that LOD activity is induced at the posttranscriptional level by l-Lys as well as by two structurally similar compounds, l-Arg and meso-2,6-diaminopimelic acid (DAP), neither of which is a substrate of the enzyme. The inducing effect of these compounds is specific for LOD activity since PpoA and PpoB are not affected by them. This study offers, for the first time, insights into the mechanisms regulating the synthesis of the antimicrobial protein lysine-epsilon-oxidase in M. mediterranea, which could be important in the microbial colonization of the seagrass P. oceanica.
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PMID:Regulation of the Marinomonas mediterranea antimicrobial protein lysine oxidase by L-lysine and the sensor histidine kinase PpoS. 2065 78


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