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61.
Many bacteria biosynthesize 3,4-dihydroxyphenylacetate 2,3-dioxygenases for growth on aromatic acids, but gram-negative organisms have been most extensively studied. A gram-positive strain containing 2,3-dioxygenase activity was identified as Arthrobacter strain Mn-1. The 2,3-dioxygenase from strain Mn-1 was purified to homogeneity by fast protein liquid chromatography with a Mono Q anion-exchange column. Rabbit polyclonal antidioxygenase antibodies were prepared. Ouchterlony double-diffusion and Western blotting (immunoblotting) protocols were used to probe the distribution of the Mn-1 dioxygenase antigen in soil bacteria. Fourteen 2,3-dioxygenase-containing Bacillus and Pseudomonas strains did not contain immunologically cross-reactive proteins. Six of eight Arthrobacter strains contained 2,3-dioxygenase activity, and all of them produced cross-reactive proteins. The data presented here suggest that a unique type of dioxygenase is geographically widespread but is taxonomically confined to Arthrobacter soil bacteria. 相似文献
62.
63.
Dynamics in microbial immobilization and transformations of phosphorus in highly weathered subtropical soil following organic amendments 总被引:9,自引:0,他引:9
Jinshui Wu Min Huang He-Ai Xiao Yi-Rong Su Cheng-Li Tong Dao-You Huang J. Keith Syers 《Plant and Soil》2007,290(1-2):333-342
To improve knowledge on the role of microbial processes in phosphorus (P) transformations in highly weathered subtropical
soil, dynamics in microbial biomass C (BC) and P (BP), and Olsen-P in a subtropical Ultisol following amendments with glucose at 2 g C kg−1 soil (G2) and rice straw at 2 and 4 g C kg−1 soil (RS2 and RS4) was studied during a 43-day incubation period at 25°C and 45% of soil water-holding capacity. By 3 days,
the amount of soil BC had increased about 3.2, 1.7, and 2.6 times for G2, RS2, and RS4, respectively. The amount of soil BC significantly decreased between 3 and 7 days for G2 and 3 and 14 days for RS4, and thereafter remained almost steady throughout
the 43-day incubation period, at levels about 1.6–2.4 times larger than for the control (no organic amendment; CK). The amount
of soil BP for G2 and RS4 almost doubled by 3 or 7 days, then remained relatively steady, and for RS2, maintained relatively constant
(6.7–8.2 mg kg−1 soil) throughout 43-day incubation period, whereas it declined by about 50% for CK. A significant decrease (3.5 mg kg−1 soil) in Olsen-P occurred in G2 by 3 days; indicating a close response of available P to microbial immobilization. Also,
the amounts of Al- and Fe-bound P in G2 and Fe-bound-P in RS4 decreased significantly, as determined at 43 days. In conclusion,
organic amendment enhances microbial immobilization and transformations of P, but the turnover of BP behaves in different patterns as BC in highly weathered subtropical soil. 相似文献
64.
65.
Endostatin inhibits VEGF-induced endothelial cell migration and tumor growth independently of zinc binding. 总被引:64,自引:0,他引:64
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N Yamaguchi B Anand-Apte M Lee T Sasaki N Fukai R Shapiro I Que C Lowik R Timpl B R Olsen 《The EMBO journal》1999,18(16):4414-4423
Endostatin, produced as recombinant protein in human 293-EBNA cells, inhibits the migration of human umbilical vein endothelial cells (HUVECs) in response to vascular endothelial growth factor (VEGF) in a dose-dependent manner and prevents the subcutaneous growth of human renal cell carcinomas in nude mice at concentrations and in doses that are from 1000- to 100 000-fold lower than those previously reported. The inhibition of migration is not affected by mutations which eliminate Zn or heparin binding and inhibition of tumor growth does not depend on Zn binding. The results of the migration assays suggest that endostatin causes a block at one or more steps in VEGF-induced migration, while VEGF in turn can cause a block of the inhibition by endostatin of VEGF-induced migration of HUVECs. 相似文献
66.
Van QN Issaq HJ Jiang Q Li Q Muschik GM Waybright TJ Lou H Dean M Uitto J Veenstra TD 《Journal of proteome research》2008,7(2):630-639
High-resolution, liquid state nuclear magnetic resonance (NMR) spectroscopy is a popular platform for metabolic profiling because the technique is nondestructive, quantitative, reproducible, and the spectra contain a wealth of biochemical information. Because of the large dynamic range of metabolite concentrations in biofluids, statistical analyses of one-dimensional (1D) proton NMR data tend to be biased toward selecting changes in more abundant metabolites. Although two-dimensional (2D) proton-proton experiments can alleviate spectral crowding, they have been mainly used for structural determination. In this study, 2D total correlation spectroscopy NMR was used to compare the global metabolic profiles of urine obtained from wild-type and Abcc6-knockout mice. The 2D data were compared to an improved 1D experiment in which signal contributions from macromolecules and the urea peak have been spectroscopically removed for more accurate quantitation of low-abundance metabolites. Although statistical models from both 1D and 2D data could differentiate samples acquired from the two groups of mice, only the 2D spectra allowed the characterization of statistically relevant changes in the low-abundance metabolites. While acquisition of the 2D data require more time, the data obtained resulted in a more meaningful and comprehensive metabolic profile, aided in metabolite identifications, and minimized ambiguities in peak assignments. 相似文献
67.
Ivo H. J. Ploemen Miguel Prudêncio Bruno G. Douradinha Jai Ramesar Jannik Fonager Geert-Jan van Gemert Adrian J. F. Luty Cornelus C. Hermsen Robert W. Sauerwein Fernanda G. Baptista Maria M. Mota Andrew P. Waters Ivo Que Clemens W. G. M. Lowik Shahid M. Khan Chris J. Janse Blandine M. D. Franke-Fayard 《PloS one》2009,4(11)
The quantitative analysis of Plasmodium development in the liver in laboratory animals in cultured cells is hampered by low parasite infection rates and the complicated methods required to monitor intracellular development. As a consequence, this important phase of the parasite''s life cycle has been poorly studied compared to blood stages, for example in screening anti-malarial drugs. Here we report the use of a transgenic P. berghei parasite, PbGFP-Luccon, expressing the bioluminescent reporter protein luciferase to visualize and quantify parasite development in liver cells both in culture and in live mice using real-time luminescence imaging. The reporter-parasite based quantification in cultured hepatocytes by real-time imaging or using a microplate reader correlates very well with established quantitative RT-PCR methods. For the first time the liver stage of Plasmodium is visualized in whole bodies of live mice and we were able to discriminate as few as 1–5 infected hepatocytes per liver in mice using 2D-imaging and to identify individual infected hepatocytes by 3D-imaging. The analysis of liver infections by whole body imaging shows a good correlation with quantitative RT-PCR analysis of extracted livers. The luminescence-based analysis of the effects of various drugs on in vitro hepatocyte infection shows that this method can effectively be used for in vitro screening of compounds targeting Plasmodium liver stages. Furthermore, by analysing the effect of primaquine and tafenoquine in vivo we demonstrate the applicability of real time imaging to assess parasite drug sensitivity in the liver. The simplicity and speed of quantitative analysis of liver-stage development by real-time imaging compared to the PCR methodologies, as well as the possibility to analyse liver development in live mice without surgery, opens up new possibilities for research on Plasmodium liver infections and for validating the effect of drugs and vaccines on the liver stage of Plasmodium. 相似文献
68.
Chunxiu Shen Zhiqun Que Yumei Xia Ning Tang Ding Li Ronghua He Mengliang Cao 《Journal of Plant Biology》2017,60(6):539-547
Plant annexins are Ca2+-dependent phospholipid-binding proteins and exist as multigene families in plants. They are implicated in the regulation of plant development as well as protection from environmental stresses. In this study, the rice annexin gene OsAnn3 knockout was performed via the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated proteins) mediated genome editing. Thus, mutant plantlets were successfully obtained. We identified cold tolerance phenotype of T1 mutant lines from T0 biallelic mutants using the 4~6°C for 3 days cold treatment. The results showed that REC (the relative electrical conductivity) of T1 mutant lines was increased, and the survival ratio of T1 mutant lines was decreased dramatically compared with the wild type after the exposure to cold treatment. It was suggested that OsAnn3 was involved in cold tolerance of rice. 相似文献
69.
Parental cooperation in a changing climate: fluctuating environments predict shifts in care division
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Orsolya Vincze András Kosztolányi Zoltán Barta Clemens Küpper Monif Alrashidi Juan A. Amat Araceli Argüelles Ticó Fiona Burns John Cavitt Warren C. Conway Medardo Cruz‐López Atahualpa Eduardo Desucre‐Medrano Natalie dos Remedios Jordi Figuerola Daniel Galindo‐Espinosa Gabriel E. García‐Peña Salvador Gómez Del Angel Cheri Gratto‐Trevor Paul Jönsson Penn Lloyd Tomás Montalvo Jorge Enrique Parra Raya Pruner Pinjia Que Yang Liu Sarah T. Saalfeld Rainer Schulz Lorenzo Serra James J. H. St Clair Lynne E. Stenzel Michael A. Weston Maï Yasué Sama Zefania Tamás Székely 《Global Ecology and Biogeography》2017,26(3):347-358
70.
Xiaotong Wang Li Li Yabing Zhu Xiaorui Song Xiaodong Fang Ronglian Huang Huayong Que Guofan Zhang 《Molecular biology reports》2014,41(11):7067-7071
Two calcium carbonate crystal polymorphs, aragonite and calcite, are the main inorganic components of mollusk shells. Some fossil evidences suggest that aragonite shell is more ancient than calcite shell for the Bivalvia. But, the molecular biology evidence for the above deduction is absent. In this study, we searched for homologs of bivalve aragonite-related and calcite-related shell proteins in the oyster genome, and found that no homologs of calcite-related shell protein but some homologs of aragonite-related shell proteins in the oyster genome. We explained the results as the new evidence to support that aragonite shells are more ancient than calcite shells in bivalves combined the published biogeological and seawater chemistry data. 相似文献