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71.
72.
Effect of culture conditions on manganese peroxidase production and activity by some white rot fungi 总被引:4,自引:0,他引:4
The ligninolytic system of white rot fungi is primarily composed of lignin peroxidase, manganese peroxidase (MnP) and laccase.
The present work was carried out to determine the best culture conditions for production of MnP and its activity in the relatively
little-explored cultures of Dichomitus squalens, Irpex flavus and Polyporus sanguineus, as compared with conditions for Phanerochaete chrysosporium and Coriolus versicolor. Studies on enzyme production under different nutritional conditions revealed veratryl alcohol, guaiacol, Reax 80 and Polyfon
H to be excellent MnP inducers.
Electronic Publication 相似文献
73.
Characterisation of glutathione transferases and glutathione peroxidases in pea (Pisum sativum) 总被引:2,自引:0,他引:2
Robert Edwards 《Physiologia plantarum》1996,98(2):594-604
74.
Distant homology relationships among proteins with many transmembrane regions (TMs) are difficult to detect as they are clouded by the TMs’ hydrophobic compositional bias and mutational divergence in connecting loops. In the case of several GPI lipid anchor biosynthesis pathway components, the hidden evolutionary signal can be revealed with dissectHMMER, a sequence similarity search tool focusing on fold-critical, high complexity sequence segments. We find that a sequence module with 10 TMs in PIG-W, described as acyl transferase, is homologous to PIG-U, a transamidase subunit without characterized molecular function, and to mannosyltransferases PIG-B, PIG-M, PIG-V and PIG-Z. We conclude that this new, membrane-embedded domain named BindGPILA functions as the unit for recognizing, binding and stabilizing the GPI lipid anchor in a modification-competent form as this appears the only functional aspect shared among all proteins. Thus, PIG-U's likely molecular function is shuttling/presenting the anchor in a productive conformation to the transamidase complex. 相似文献
75.
Reddening of leaves is a physiological disorder in cotton induced by different abiotic stresses. Dramatic biochemical changes occurred in reddening leaves: strong accumulation of anthocyanins and drop of chlorophyll content, important increase of proline content and peroxidase activity. The lipid peroxide content indicative of membrane fragmentation was decreased. In this way a multicomponent system encompassing anthocyanins, proline, and peroxidase may act coordinately to overcome abiotic stress in cotton. 相似文献
76.
Two pure peroxidase isoenzymes B1 and D4 were isolated from the upper parts of 10-day-old wheat seedlings by means of gel and ion-exchange chromatography. Their MWs were 85000 and 24000 respectively. B1 was unstable and under various conditions it was converted to another isoenzyme, electrophoretically identical with D4. B1 contains about 40% of neutral sugars: 17.2% arabinose, 15.3% galactose, 5% glucose and traces of mannose. D4 is free of neutral sugars. None of the isoenzymes contained amino sugars. B1 oxidizes ferulic and p-coumaric acids. This oxidation has two pH optima of 4.4 and 5.4–5.6 and is inhibited by high concentrations of substrates, cyanide and azide. B1 oxidizes IAA in the presence of phenolic cofactor and Mn2+ ions. IAA oxidation has two pH optima of 4.5 and 5.6 and is inhibited by high substrate concentration, cyanide and azide, and by a number of indole derivatives. The main products of IAA oxidation are 3-methyleneoxindole and indole-3-methanol. o- and p- diphenols induce a lag period prior to IAA oxidation. Ferulic acid is oxidized during this lag period, probably to a dimer. B1 is able to produce H2O2 from oxygen. Mn2+ ions, a phenolic cofactor and an electron donor (IAA or NADH) are needed. B1 oxidizes α-keto-γ- methylmercaptobutyric acid to ethylene. D4 has a low peroxidatic activity and is inactive as an IAA oxidase. Thus B1 is probably an active cell wall-bound peroxidase isoenzyme, whereas D4 is its decomposition product. 相似文献
77.
Jeremy R. Lohman Ming Ma Marianne E. Cuff Lance Bigelow Jessica Bearden Gyorgy Babnigg Andrzej Joachimiak George N. Phillips Jr. Ben Shen 《Proteins》2014,82(7):1210-1218
Carrier proteins (CPs) play a critical role in the biosynthesis of various natural products, especially in nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) enzymology, where the CPs are referred to as peptidyl‐carrier proteins (PCPs) or acyl‐carrier proteins (ACPs), respectively. CPs can either be a domain in large multifunctional polypeptides or standalone proteins, termed Type I and Type II, respectively. There have been many biochemical studies of the Type I PKS and NRPS CPs, and of Type II ACPs. However, recently a number of Type II PCPs have been found and biochemically characterized. In order to understand the possible interaction surfaces for combinatorial biosynthetic efforts we crystallized the first characterized and representative Type II PCP member, BlmI, from the bleomycin biosynthetic pathway from Streptomyces verticillus ATCC 15003. The structure is similar to CPs in general but most closely resembles PCPs. Comparisons with previously determined PCP structures in complex with catalytic domains reveals a common interaction surface. This surface is highly variable in charge and shape, which likely confers specificity for interactions. Previous nuclear magnetic resonance (NMR) analysis of a prototypical Type I PCP excised from the multimodular context revealed three conformational states. Comparison of the states with the structure of BlmI and other PCPs reveals that only one of the NMR states is found in other studies, suggesting the other two states may not be relevant. The state represented by the BlmI crystal structure can therefore serve as a model for both Type I and Type II PCPs. Proteins 2014; 82:1210–1218. © 2013 Wiley Periodicals, Inc. 相似文献
78.
Characterization of the tunicamycin gene cluster unveiling unique steps involved in its biosynthesis
Wenqing Chen Dongjing Qu Lipeng Zhai Meifeng Tao Yemin Wang Shuangjun Lin Neil P. J. Price Zixin Deng 《蛋白质与细胞》2010,1(12):1093
Tunicamycin, a potent reversible translocase I inhibitor, is produced by several Actinomycetes species. The tunicamycin structure is highly unusual, and contains an 11-carbon dialdose sugar and an α, β -1″,11′-glycosidic linkage. Here we report the identification of a gene cluster essential for tunicamycin biosynthesis by high-throughput heterologous expression (HHE) strategy combined with a bioassay. Introduction of the genes into heterologous non-producing Streptomyces hosts results in production of tunicamycin by these strains, demonstrating the role of the genes for the biosynthesis of tunicamycins. Gene disruption experiments coupled with bioinformatic analysis revealed that the tunicamycin gene cluster is minimally composed of 12 genes (tunA– tunL ). Amongst these is a putative radical SAM enzyme (Tun B) with a potentially unique role in biosynthetic carbon-carbon bond formation. Hence, a seven-step novel pathway is proposed for tunicamycin biosynthesis. Moreover, two gene clusters for the potential biosynthesis of tunicamycin-like antibiotics were also identified in Streptomyces clavuligerus ATCC 27064 and Actinosynnema mirums DSM 43827. These data provide clarification of the novel mechanisms for tunicamycin biosynthesis, and for the generation of new-designer tunicamycin analogs with selective/enhanced bioactivity via combinatorial biosynthesis strategies. 相似文献
79.
Light stimulates the synthesis of amaranthin in Amaranthus caudatus var. viridis. Evidence suggests that this stimulation is markedly dependent on seedling age. Synthesis is controlled by both a “low-energy” red/far-red reversible phytochrome system and an HER at least partially under phytochrome control. In seedlings exposed to light, synthesis is promoted by exogenously applied DOPA and tyrosine. It is suggested that at least two light-promoted reactions occur in the biosynthetic pathway; one between tyrosine and DOPA and a second between DOPA and amaranthin. 相似文献
80.