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711.
Sunil Kumar Sirohi Prasanta Kumar Choudhury Anil Kumar Puniya Dheer Singh Sumit Singh Dagar Nasib Singh 《Annals of microbiology》2013,63(4):1571-1577
Fiber degradation in the ruminant digestive process is a major activity accomplished by rumen microbes, a process in which the role of fungi is important. Therefore, the present study was conducted to establish the community structure of anaerobic rumen fungi in cattle fed on a high fiber diet using molecular approaches. Total community DNA was extracted, and the ribosomal internal transcribed spacer (ITS) 1 region was amplified, cloned, and sequenced. The resulting nucleotide sequences were used to construct a phylogenetic tree. A total of 52 clones were analyzed, revealing 31 different ITS1 gene phylotypes. Of these, 12 belonged to the genus Orpinomyces (48 % of clones), followed by uncultured Neocallimastigale clones (29 %), Cyllamyces spp. (9 %) and Anaeromyces spp. (8 %). Our results indicate that genus Orpinomyces dominates the rumen fungal community in Indian crossbred Karan Fries cattle. 相似文献
712.
Sreekanth Ramachandran Manoranjan Panda Kakoli Mukherjee Nilanjana Roy Choudhury Subramanyam J. Tantry Chaitanya Kumar Kedari Vasanthi Ramachandran Sreevalli Sharma V.K. Ramya Supreeth Guptha Vasan K. Sambandamurthy 《Bioorganic & medicinal chemistry letters》2013,23(17):4996-5001
Imidazo[1,2-a]pyridine-8-carboxamides as a novel antimycobacterial lead were generated by whole cell screening of a focused library against Mycobacterium tuberculosis. Herein, we describe the synthesis and structure activity relationship evaluation of this class of inhibitors and the optimization of physicochemical properties. These are selective inhibitors of Mycobacterium tuberculosis with no activity on either gram positive or gram negative pathogens. 相似文献
713.
Hassanul G. Choudhury Konstantinos Beis 《Protein science : a publication of the Protein Society》2013,22(9):1287-1293
Bacterial response regulators (RRs) can regulate the expression of genes that confer antibiotic resistance; they contain a receiver and an effector domain and their ability to bind DNA is based on the dimerization state. This is triggered by phosphorylation of the receiver domain by a kinase. However, even in the absence of phosphorylation RRs can exist in equilibrium between monomers and dimers with phosphorylation shifting the equilibrium toward the dimer form. We have determined the crystal structure of the unphosphorylated dimeric BaeR from Escherichia coli. The dimer interface is formed by a domain swap at the receiver domain. In comparison with the unphosphorylated dimeric PhoP from Mycobacterium tuberculosis, BaeR displays an asymmetry of the effector domains. 相似文献
714.
Marzena Rola-?uszczak Aneta Pluta Monika Olech Irina Donnik Maxim Petropavlovskiy Anton Gerilovych Irina Vinogradova Bhudipa Choudhury Jacek Ku?mak 《PloS one》2013,8(3)
Recent studies have shown that bovine leukemia virus (BLV) sequences can be classified into seven distinct genotypes based on full gp51 sequence. This classification was based on available sequence data that mainly represented the BLV population that is circulating in cattle from the US and South America. In order to aid with a global perspective inclusion of data from Eastern Europe is required. In this study we examined 44 BLV isolates from different geographical regions of Poland, Belarus, Ukraine, and Russia. Phylogenetic analysis based on a 444bp fragment of env gene revealed that most of isolates belonged to genotypes 4 and 7. Furthermore, we confirmed the existence of a new genotype, genotype 8, which was highly supported by phylogenetic computations. A significant number of amino acid substitutions were found in the sequences of the studied Eastern European isolates, of which 71% have not been described previously. The substitutions encompassed mainly the C-part of the CD4+ epitope, zinc binding peptide region, CD8+ T cell epitope, and overlapping linear epitope E. These observations highlight the use of sequence data to both elucidate phylogenetic relationships and the potential effect on serological detection of geographically diverse isolates. 相似文献
715.
Roy S Roy Choudhury S Mukherjee SK Sengupta DN 《Archives of biochemistry and biophysics》2007,468(1):22-31
PCNA is well known as a component of DNA replication system and plays important roles in multiple cellular pathways in addition to replication and repair. In this work we have demonstrated the physical and functional interaction between tobacco PCNA and mungbean ddNTP-sensitive DNA polymerase which shares many physicochemical properties with family X-DNA polymerases except with the moderately processive mode of nucleotide incorporation. We have shown here that recombinant PCNA binds directly to mungbean DNA polymerase as revealed in affinity chromatography, pull-down and co-immunoprecipitation approaches. In vitro DNA polymerase activity assay and processivity analyses indicated recombinant PCNA specifically stimulates both activity and processivity of mungbean DNA polymerase. These observations lead to interesting speculation about the functional significance of the ddNTP-sensitive enzyme in replication event in higher plants since the enzyme has been shown to be active and expressed at an elevated level during the endoreduplication stages in developing mungbean seeds. 相似文献
716.
Neganova I Al-Qassab H Heffron H Selman C Choudhury AI Lingard SJ Diakonov I Patterson M Ghatei M Bloom SR Franks S Huhtaniemi I Hardy K Withers DJ 《Biology of reproduction》2007,76(6):1045-1053
Insulin receptor signaling regulates female reproductive function acting in the central nervous system and ovary. Female mice that globally lack insulin receptor substrate (IRS) 2, which is a key mediator of insulin receptor action, are infertile with defects in hypothalamic and ovarian functions. To unravel the tissue-specific roles of IRS2, we examined reproductive function in female mice that lack Irs2 only in the neurons. Surprisingly, these animals had minimal defects in pituitary and ovarian hormone levels, ovarian anatomy and function, and breeding performance, which indicates that the central nervous system IRS2 is not an obligatory signaling component for the regulation of reproductive function. Therefore, we undertook a detailed analysis of ovarian function in a novel Irs2 global null mouse line. Comparative morphometric analysis showed reduced follicle size, increased numbers of atretic follicles, as well as impaired oocyte growth and antral cavity development in Irs2 null ovaries. Granulosa cell proliferation was also defective in the Irs2 null ovaries. Furthermore, the insulin- and eCG-stimulated phosphoinositide-3-OH kinase signaling events, which included phosphorylation of Akt/protein kinase B and glycogen synthase kinase 3-beta, were impaired, whereas mitogen-activated protein kinase signaling was preserved in Irs2 null ovaries. These abnormalities were associated with reduced expression of cyclin D2 and increased CDKN1B levels, which indicates dysregulation of key components of the cell cycle apparatus implicated in ovarian function. Our data suggest that ovarian rather than central nervous system IRS2 signaling is important in the regulation of female reproductive function. 相似文献
717.
In our recently published study, we provided in vitro as well as in vivo data demonstrating the involvement of TRM2/RNC1 in homologous recombination based repair (HRR) of DNA double strand breaks (DSBs), in support of such claims reported earlier.
To further validate its role in DNA DSB processing, our present study revealed that the trm2 single mutant displays higher sensitivity to persistent induction of specific DSBs at the MAT locus by HO-endonuclease with
higher sterility rate among the survivors compared to wild type (wt) or exo1 single mutants. Intriguingly, both sensitivity and sterility rate increased dramatically in trm2exo1 double mutants lacking both endo-exonucleases with a progressively increased sterility rate in trm2exo1 double mutants with short-induction periods, reaching a very high level of sterility with persistent DSB inductions. Mutation
analysis of the mating type (MAT) locus among the sterile survivors with persistent HO-induction in trm2 and exo1 single mutants as well as in trm2exo1 double mutants revealed a similar small insertions and deletions events, characteristic of non-homologous end joining (NHEJ)
that might have occurred due to the lack of proper processing function in these mutants. In addition, trm2ku80 and trm2rad52 double mutants also displayed significantly higher sterility with persistent DSB induction compared to ku80 and rad52 single mutants, respectively, exhibiting a mutation spectra that shifted from base substitution (in ku80 and rad52 single mutants) to small insertions and deletions in the double mutants (in trm2ku80 and trm2rad52 mutants). These data indicate a defective processing in absence of TRM2, with a synergistic effect of TRM2, and EXO1 in such processing. 相似文献
718.
Choudhury SD DasGupta S Norris GE 《International journal of biological macromolecules》2007,40(4):351-361
Cross-linking agents play an important part in the physical properties of collagen based biomaterials. Oxazolidines are novel aldehydic tanning agents that are widely used to stabilise collagens in the leather industry. The exact mechanism through which they cross-link collagens is, however, not well understood. When they are combined with vegetable tannins, it is thought that oxazolidines form carbocationic intermediates through ring opening, which are then able to interact with the amino acid side chains of collagens and flavonoid ring systems of vegetable tannins. In this study, the interactions of oxazolidines, with collagens, have been investigated using a number of analytical techniques. High pressure liquid chromatography (HPLC) analysis of oxazolidine tanned collagen samples showed that there is an irreversible reaction with tyrosine side chains. Mass spectrometry (MS) revealed the formation of a Schiff's base adduct with lysine residues, which was reversible in nature. MS analysis of reaction of oxazolidines with a model peptide Suc-Ala-Phe-Lys-AMC in presence of NaCNBH(3), indicated the formation of a product with an increase in molecular weight of 28 kD characteristic of the addition of two methyl groups to lysine. Differential scanning calorimetry showed a synergistic effect for combination tannage, with best results being obtained when vegetable tan was added prior to the aldehydic tanning agents. Circular dichroism (CD) studies of collagen in presence of the more reactive oxazolidine A showed that there was a loss in ellipticity simply because of aggregation of collagen molecules rather than a change in the secondary structure. Based on the results obtained, a scheme has been proposed to explain the possible mechanism of action of oxazolidines with the collagen amino acid side chains. 相似文献
719.
Five brands of antidiabetic herbal formulations as tablets, Diabetex, Divya Madhu Nashini, Jambrushila, Diabeticin, and Madhumeh Nashini, from different pharmacies were analyzed for six minor (Na, K, Ca, Cl, Mg, and P) and 20 trace (As, Ba, Br, Ce, Co, Cr, Cs,
Cu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V, and Zn) elements by thermal neutron irradiation followed by high-resolution
gamma ray spectrometry. Further Ni, Cd, and Pb were determined by atomic absorption spectrophotometry. Most elements vary
in a narrow range by a factor of 2–4 while a few others vary in a wide range, e.g., Na (0.05–0.67 mg/g), Mn (26.7–250 μg/g),
and V (0.26–2.50 μg/g). All the five brands contain K, Cl, Mg, P, and Ca as minor constituents along with mean trace amounts
of Cr (2.11 ± 0.67 μg/g), Cu (15.7 ± 7.11 μg/g), Fe (459 ± 171 μg/g), Mn (143 ± 23 μg/g), Se (238 ± 112 ng/g), and V (0.99 ± 0.93 μg/g).
Jambrushila is enriched in Na, Ca, Mg, Cl, Fe, Cu, Se, and Zn, essential nutrients responsible for curing diabetes. Dietary intake of
Mn, Fe, and Cu are greater than 10% of the recommended dietary allowance, whereas that for Zn and Se is less than 2%. Mean
contents of toxic elements (As, Cd, Hg, and Pb) were found below permissible limits except in Jambrushila. Cr and Zn were inversely correlated with r = −0.81, whereas Rb and Cs exhibit linear correlation (r = 0.93) in five brands. C, H, N analysis showed C ∼ 55%, H ∼ 12%, and N ∼ 2% with a total of ∼70% organic matter. However,
thermal decomposition studies at 700°C suggest less than 5% nonvolatile metal oxides. Herbal formulations contain minor and
trace elements in bioavailable forms that favorably influence glucose tolerance and possibly increase the body’s ability to
ameliorate development of diabetes. 相似文献
720.
Composition and distribution of benthic isopod (Crustacea,Malacostraca) families off the Victoria-Land Coast (Ross Sea,Antarctica) 总被引:1,自引:0,他引:1
The benthic fauna off the Victoria-Land-Coast, Ross Sea (Antarctica) was investigated during the 19th Italica expedition in February 2004. Samples were taken along a latitudinal transect from Cape Adare down to Terra Nova Bay at water
depths ranging from 84 to 515 m. A Rauschert dredge was used at 18 stations to collect epi- and infaunal macrobenthos. 9,494
specimens of Isopoda were collected, representing 19 families. Desmosomatidae were the most abundant family (35,297 ind/1,000 m2), followed by Paramunnidae (23,973 ind/1,000 m2). Paramunnidae was the most frequent taxon and was collected at all stations, in contrast to the Desmosomatidae, which did
not occur at any station off Cape Adare. 相似文献