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111.
112.
Deni Pranowo Nuryono Ali Agus Sri Wedhastri Elisabeth Viktoria Reiter Ebrahim Razzazi-Fazeli Jürgen Zentek 《Mycotoxin Research》2013,29(3):135-139
Samples from large (100–200 tons) batches of palm kernel cake (PKC, n?=?20) and copra meal (CM, n?=?13) were collected at production facilities of four Indonesian feed mill manufacturers and analysed for aflatoxin B1 (AFB1) by ELISA. Recoveries using spiked samples ranged from 86 to 113 %, with relative standard deviations of <9 % (PKC) and <6 % (CM). All batches were positive for AFB1: in PKC, at levels of 5.8–93.1 μg/kg (mean 49 μg/kg), and in CM, at levels of 1.1–147 μg/kg (mean 38.1 μg/kg). AFB1 levels were, in most batches, below the maximum level (100 μg/kg) recommended by the National Standardisation Agency, Republic of Indonesia. However, about half of the batches exceeded both the European Union and USA regulations for AFB1 in animal feed. In conclusion, serious efforts are necessary to control production, storage and shipment of palm kernel cake and copra meal for feed purposes, and clearly not only for products intended for export but also to reduce AFB1 levels in domestic Indonesian feed. 相似文献
113.
Mycobacterium leprae is closely related to Mycobacterium tuberculosis, yet causes a very different illness. Detailed genomic comparison between these two species of mycobacteria reveals that the decaying M. leprae genome contains less than half of the M. tuberculosis functional genes. The reduction of genome size and accumulation of pseudogenes in the M. leprae genome is thought to result from multiple recombination events between related repetitive sequences, which provided the impetus to investigate the recombination-like activities of RecA protein. In this study, we have cloned, over-expressed and purified M. leprae RecA and compared its activities with that of M. tuberculosis RecA. Both proteins, despite being 91% identical at the amino acid level, exhibit strikingly different binding profiles for single-stranded DNA with varying GC contents, in the ability to catalyze the formation of D-loops and to promote DNA strand exchange. The kinetics and the extent of single-stranded DNA-dependent ATPase and coprotease activities were nearly equivalent between these two recombinases. However, the degree of inhibition exerted by a range of ATP:ADP ratios was greater on strand exchange promoted by M. leprae RecA compared to its M. tuberculosis counterpart. Taken together, our results provide insights into the mechanistic aspects of homologous recombination and coprotease activity promoted by M. lepare RecA, and further suggests that it differs from the M. tuberculosis counterpart. These results are consistent with an emerging concept of DNA-sequence influenced structural differences in RecA nucleoprotein filaments and how these differences reflect on the multiple activities associated with RecA protein. 相似文献
114.
Michael Kessler Yann Clough Ramadhanil Pitopang Daniela Leitner Sri S. Tjitrosoedirdjo 《Biotropica》2011,43(6):755-762
Tropical secondary forest and agroforestry systems have been identified as important refuges for the local species diversity of birds and other animal groups, but little is known about the importance of these systems for terrestrial herbs. In particular, few studies report how the conversion from tropical forest to technified cacao plantation affects the species richness and the community structure of herbs. We conducted surveys in 43 cacao plantations along the border of the Lore Lindu National Park in Central Sulawesi, ranging from agroforests to technified cacao, categorizing the plantations as rustic cacao, planted shade cacao, and technified cacao. We recorded 91 herb species. Of the 74 species determined to species level, 21 were also found in natural forests, while 53 were recorded only in agricultural habitats. Araceae was the most forest‐dependent plant family while Asteraceae included the highest number of nonforest species. Overall, the presence of forest species was confined to moderately intensively managed rustic and planted shaded plantations. Distance from the forest, which has been identified as a crucial parameter for the diversity and composition of other taxa in cacao agroforests, only played a minimal role for herbs. Our study suggests that native forest herbs maybe more vulnerable to forest conversion than animal groups. The intensification of cacao plantation management increases the presence of weedy species to the detriment of native forest species. 相似文献
115.
Dumbala Srinivas Reddy Pooja Bhatnagar-Mathur Katamreddy Sri Cindhuri Kiran K. Sharma 《PloS one》2013,8(10)
The quantitative real-time PCR (qPCR) based techniques have become essential for gene expression studies and high-throughput molecular characterization of transgenic events. Normalizing to reference gene in relative quantification make results from qPCR more reliable when compared to absolute quantification, but requires robust reference genes. Since, ideal reference gene should be species specific, no single internal control gene is universal for use as a reference gene across various plant developmental stages and diverse growth conditions. Here, we present validation studies of multiple stably expressed reference genes in cultivated peanut with minimal variations in temporal and spatial expression when subjected to various biotic and abiotic stresses. Stability in the expression of eight candidate reference genes including ADH3, ACT11, ATPsyn, CYP2, ELF1B, G6PD, LEC and UBC1 was compared in diverse peanut plant samples. The samples were categorized into distinct experimental sets to check the suitability of candidate genes for accurate and reliable normalization of gene expression using qPCR. Stability in expression of the references genes in eight sets of samples was determined by geNorm and NormFinder methods. While three candidate reference genes including ADH3, G6PD and ELF1B were identified to be stably expressed across experiments, LEC was observed to be the least stable, and hence must be avoided for gene expression studies in peanut. Inclusion of the former two genes gave sufficiently reliable results; nonetheless, the addition of the third reference gene ELF1B may be potentially better in a diverse set of tissue samples of peanut. 相似文献
116.
α-Glucosidase inhibitor has considerable potential as a diabetes mellitus type 2 drug because it prevents the digestion of carbohydrates. The search for the constituents reducing α-glucosidase activity led to the finding of active compounds in the fruiting body of Ganoderma lucidum. The CHCl3 extract of the fruiting body of G. lucidum was found to show inhibitory activity on α-glucosidase in vitro. The neutral fraction, with an IC50 of 88.7 μg/ml, had stronger inhibition than a positive control, acarbose, with an IC50 of 336.7 μg/ml (521.5 μM). The neutral fraction was subjected to silica gel column chromatography and repeated p-HPLC to provide an active compound, (3β,24E)-lanosta-7,9(11),24-trien-3,26-diol (ganoderol B). It was found to have high α-glucosidase inhibition, with an IC50 of 48.5 μg/ml (119.8 μM). 相似文献
117.
The giant freshwater prawn Macrobrachium rosenbergii is cultivated essentially in Southern and South-eastern Asian countries such as continental China, India, Thailand and Taiwan. To date, only two viral agents have been reported from this prawn. The first (HPV-type virus) was observed by chance 25 years ago in hypertrophied nuclei of hepatopancreatic epithelial cells and is closely related to members of the Parvoviridae family. The second, a nodavirus named MrNV, is always associated with a non-autonomous satellite-like virus (XSV), and is the origin of so-called white tail disease (WTD) responsible for mass mortalities and important economic losses in hatcheries and farms for over a decade. After isolation and purification of these two particles, they were physico-chemically characterized and their genome sequenced. The MrNV genome is formed with two single linear ss-RNA molecules, 3202 and 1250 nucleotides long, respectively. Each RNA segment contains only one ORF, ORF1 coding for the RNA-dependant RNA polymerase located on the long segment and ORF2 coding for the structural protein CP-43 located on the small one. The XSV genome (linear ss-RNA), 796 nucleotides long, contains a single ORF coding for the XSV coat protein CP-17. The XSV does not contain any RdRp gene and consequently needs the MrNV polymerase to replicate. 相似文献
118.
Chen WY Xu Y Cho IM Oruganti SV Foster MP Gopalan V 《Journal of molecular biology》2011,411(2):368-383
Ribonuclease P (RNase P) is a ribonucleoprotein complex that utilizes a Mg(2+)-dependent RNA catalyst to cleave the 5' leader of precursor tRNAs (pre-tRNAs) and generate mature tRNAs. The bacterial RNase P protein (RPP) aids RNase P RNA (RPR) catalysis by promoting substrate binding, Mg(2+) coordination and product release. Archaeal RNase P comprises an RPR and at least four RPPs, which have eukaryal homologs and function as two binary complexes (POP5·RPP30 and RPP21·RPP29). Here, we employed a previously characterized substrate-enzyme conjugate [pre-tRNA(Tyr)-Methanocaldococcus jannaschii (Mja) RPR] to investigate the functional role of a universally conserved uridine in a bulge-helix structure in archaeal RPRs. Deletion of this bulged uridine resulted in an 80-fold decrease in the self-cleavage rate of pre-tRNA(Tyr)-MjaΔU RPR compared to the wild type, and this defect was partially ameliorated upon addition of either RPP pair. The catalytic defect in the archaeal mutant RPR mirrors that reported in a bacterial RPR and highlights a parallel in their active sites. Furthermore, an N-terminal deletion mutant of Pyrococcus furiosus (Pfu) RPP29 that is defective in assembling with its binary partner RPP21, as assessed by isothermal titration calorimetry and NMR spectroscopy, is functional when reconstituted with the cognate Pfu RPR. Collectively, these results indicate that archaeal RPPs are able to compensate for structural defects in their cognate RPR and vice-versa, and provide striking examples of the cooperative subunit interactions critical for driving archaeal RNase P toward its functional conformation. 相似文献
119.
Xu Q Saikatendu KS Krishna SS McMullan D Abdubek P Agarwalla S Ambing E Astakhova T Axelrod HL Carlton D Chiu HJ Clayton T DiDonato M Duan L Elsliger MA Feuerhelm J Grzechnik SK Hale J Hampton E Han GW Haugen J Jaroszewski L Jin KK Klock HE Knuth MW Koesema E Miller MD Morse AT Nigoghossian E Okach L Oommachen S Paulsen J Reyes R Rife CL Schwarzenbacher R van den Bedem H White A Wolf G Hodgson KO Wooley J Deacon AM Godzik A Lesley SA Wilson IA 《Proteins》2007,69(2):433-439
120.
Zubieta C Joseph R Krishna SS McMullan D Kapoor M Axelrod HL Miller MD Abdubek P Acosta C Astakhova T Carlton D Chiu HJ Clayton T Deller MC Duan L Elias Y Elsliger MA Feuerhelm J Grzechnik SK Hale J Han GW Jaroszewski L Jin KK Klock HE Knuth MW Kozbial P Kumar A Marciano D Morse AT Murphy KD Nigoghossian E Okach L Oommachen S Reyes R Rife CL Schimmel P Trout CV van den Bedem H Weekes D White A Xu Q Hodgson KO Wooley J Deacon AM Godzik A Lesley SA Wilson IA 《Proteins》2007,69(2):234-243
TyrA is a member of the dye-decolorizing peroxidase (DyP) family, a new family of heme-dependent peroxidase recently identified in fungi and bacteria. Here, we report the crystal structure of TyrA in complex with iron protoporphyrin (IX) at 2.3 A. TyrA is a dimer, with each monomer exhibiting a two-domain, alpha/beta ferredoxin-like fold. Both domains contribute to the heme-binding site. Co-crystallization in the presence of an excess of iron protoporphyrin (IX) chloride allowed for the unambiguous location of the active site and the specific residues involved in heme binding. The structure reveals a Fe-His-Asp triad essential for heme positioning, as well as a novel conformation of one of the heme propionate moieties compared to plant peroxidases. Structural comparison to the canonical DyP family member, DyP from Thanatephorus cucumeris (Dec 1), demonstrates conservation of this novel heme conformation, as well as residues important for heme binding. Structural comparisons with representative members from all classes of the plant, bacterial, and fungal peroxidase superfamily demonstrate that TyrA, and by extension the DyP family, adopts a fold different from all other structurally characterized heme peroxidases. We propose that a new superfamily be added to the peroxidase classification scheme to encompass the DyP family of heme peroxidases. 相似文献