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51.
Whole cultures of Nocardia sp. NRRL 5646 reduce carboxylic acids, first to aldehydes, then to alcohols and subsequently to the corresponding acetyl
esters. This work describes an NADPH-dependent reductase responsible for catalyzing the reduction of aldehyde intermediates,
which was purified 3240-fold by a combination of Mono-Q, hydroxyapatite, and ADP-agarose chromatographies. By sodium dodecyl
sulfate–polyacrylamide gel electrophoresis, the purified enzyme ran as a single band of 47 kDa. A native molecular mass estimated
at 101 kDa indicated that the enzyme was a homodimer in the native, active state. Edman degradation indicated a unique N-terminal
sequence as NH2-X-X-Ala-Ala-Ala-Tyr-Ala-Val-Pro-Ala-Pro-Asp-Gly-Cys-Phe-Glu-Lys-Val-Thr-Ile-Glu-Arg-Arg-Glu-Leu-Gly. The enzyme catalyzed
reductions of many aryl- and alkyl-aldehyde substrates. Reactions were most favorable in the direction of aldehyde reduction
to alcohols. Journal of Industrial Microbiology & Biotechnology (2000) 25, 328–332.
Received 08 May 2000/ Accepted in revised form 20 October 2000 相似文献
52.
A. Sahai 《Biometrical journal. Biometrische Zeitschrift》1985,27(3):353-355
BEST (1974) found the variance of the minimum variance unbiased estimator of the Bernoulli parameter with an inverse sample. Noting its intricacy MIKULSKI and SMITH (1976) found bounds on this variance. SATHE (1977) developed closer bounds on it. In this paper still closer upper bound on the variance is achieved using Jensen's inequality. 相似文献
53.
54.
Hypoxia and loss of PHD2 inactivate stromal fibroblasts to decrease tumour stiffness and metastasis
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Chris D Madsen Jesper T Pedersen Freja A Venning Lukram Babloo Singh Emad Moeendarbary Guillaume Charras Thomas R Cox Erik Sahai Janine T Erler 《EMBO reports》2015,16(10):1394-1408
Cancer‐associated fibroblasts (CAFs) interact with tumour cells and promote growth and metastasis. Here, we show that CAF activation is reversible: chronic hypoxia deactivates CAFs, resulting in the loss of contractile force, reduced remodelling of the surrounding extracellular matrix and, ultimately, impaired CAF‐mediated cancer cell invasion. Hypoxia inhibits prolyl hydroxylase domain protein 2 (PHD2), leading to hypoxia‐inducible factor (HIF)‐1α stabilisation, reduced expression of αSMA and periostin, and reduced myosin II activity. Loss of PHD2 in CAFs phenocopies the effects of hypoxia, which can be prevented by simultaneous depletion of HIF‐1α. Treatment with the PHD inhibitor DMOG in an orthotopic breast cancer model significantly decreases spontaneous metastases to the lungs and liver, associated with decreased tumour stiffness and fibroblast activation. PHD2 depletion in CAFs co‐injected with tumour cells similarly prevents CAF‐induced metastasis to lungs and liver. Our data argue that reversion of CAFs towards a less active state is possible and could have important clinical implications. 相似文献
55.
Computational modeling of the N‐terminus of the human dopamine transporter and its interaction with PIP2‐containing membranes
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George Khelashvili Milka Doktorova Michelle A. Sahai Niklaus Johner Lei Shi Harel Weinstein 《Proteins》2015,83(5):952-969
The dopamine transporter (DAT) is a transmembrane protein belonging to the family of neurotransmitter:sodium symporters (NSS). Members of the NSS are responsible for the clearance of neurotransmitters from the synaptic cleft, and for their translocation back into the presynaptic nerve terminal. The DAT contains long intracellular N‐ and C‐terminal domains that are strongly implicated in the transporter function. The N‐terminus (N‐term), in particular, regulates the reverse transport (efflux) of the substrate through DAT. Currently, the molecular mechanisms of the efflux remain elusive in large part due to lack of structural information on the N‐terminal segment. Here we report a computational model of the N‐term of the human DAT (hDAT), obtained through an ab initio structure prediction, in combination with extensive atomistic molecular dynamics (MD) simulations in the context of a lipid membrane. Our analysis reveals that whereas the N‐term is a highly dynamic domain, it contains secondary structure elements that remain stable in the long MD trajectories of interactions with the bilayer (totaling >2.2 μs). Combining MD simulations with continuum mean‐field modeling we found that the N‐term engages with lipid membranes through electrostatic interactions with the charged lipids PIP2 (phosphatidylinositol 4,5‐Biphosphate) or PS (phosphatidylserine) that are present in these bilayers. We identify specific motifs along the N‐term implicated in such interactions and show that differential modes of N‐term/membrane association result in differential positioning of the structured segments on the membrane surface. These results will inform future structure‐based studies that will elucidate the mechanistic role of the N‐term in DAT function. Proteins 2015; 83:952–969. © 2015 Wiley Periodicals, Inc. 相似文献
56.
Amin Arqam Awais Muhammad Sahai Shalini Hussain Waqar Rasool Nouman 《International journal of peptide research and therapeutics》2021,27(2):1315-1329
International Journal of Peptide Research and Therapeutics - DNA replication is one of the specific processes to be considered in all the living organisms, specifically eukaryotes. The prevalence... 相似文献
57.
Sarma MV Kumar V Saharan K Srivastava R Sharma AK Prakash A Sahai V Bisaria VS 《Journal of applied microbiology》2011,111(2):456-466
Aims: Fluorescent pseudomonads are widely used as bioinoculants for improving plant growth and controlling phytopathogenic fungi. Piriformospora indica (Pi), a symbiotic root endophyte, also has beneficial effects on a number of plants. The present study focuses on the improvement of growth yields of tomato plants and control of Fusarium wilt using inorganic carrier‐based formulations of two fluorescent pseudomonad strains (R62 and R81) and Pi. Methods and Results: The inorganic carrier‐based formulations of pseudomonad strains and Pi were tested for plant growth promotion of tomato plants under glass house and field conditions. In controlled glass house experiments, 8·8‐fold increase in dry root weight and 8·6‐fold increase in dry shoot weight were observed with talcum powder‐based consortium formulation of R81 and Pi. Field trial experiments ascertained the glfass house results with a considerable amount of increase in plant growth responses, and amongst all the treatments, R81 + Pi treatment performed consistently well in field conditions with an increase of 2·6‐, 3·1‐ and 3·9‐fold increase in dry root weight, shoot weight and fruit yield, respectively. The fluorescent pseudomonad R81 and Pi also acted as biocontrol agents, as their treatments could control the incidence of wilt disease caused by Fusarium oxysporum f.sp. lycopersici in tomato plants under glass house conditions. Conclusions: The culture broths of pseudomonads R62, R81 and Pi were successfully used for development of talcum‐ and vermiculite‐based bioinoculant formulations. In controlled glasshouse experiments, the talcum‐based bioinoculant formulations performed significantly better over vermiculite‐based formulations. In field experiments the talcum‐based consortium formulation of pseudomonad R81 and Pi was most effective. Significance and Impact of the Study: This study suggests that the formulations of pseudomonad strains (R62 and R81) and Pi can be used as bioinoculants for improving the productivity of tomato plants. The application of such formulations is a step forward towards sustainable agriculture. 相似文献
58.
Hidalgo-Carcedo C Hooper S Chaudhry SI Williamson P Harrington K Leitinger B Sahai E 《Nature cell biology》2011,13(1):49-58
Collective cell migration occurs in a range of contexts: cancer cells frequently invade in cohorts while retaining cell-cell junctions. Here we show that collective invasion by cancer cells depends on decreasing actomyosin contractility at sites of cell-cell contact. When actomyosin is not downregulated at cell-cell contacts, migrating cells lose cohesion. We provide a molecular mechanism for this downregulation. Depletion of discoidin domain receptor 1 (DDR1) blocks collective cancer-cell invasion in a range of two-dimensional, three-dimensional and 'organotypic' models. DDR1 coordinates the Par3/Par6 cell-polarity complex through its carboxy terminus, binding PDZ domains in Par3 and Par6. The DDR1-Par3/Par6 complex controls the localization of RhoE to cell-cell contacts, where it antagonizes ROCK-driven actomyosin contractility. Depletion of DDR1, Par3, Par6 or RhoE leads to increased actomyosin contactility at cell-cell contacts, a loss of cell-cell cohesion and defective collective cell invasion. 相似文献
59.
Background
A variety of obstacles including bureaucracy and lack of resources have interfered with timely detection and reporting of dengue cases in many endemic countries. Surveillance efforts have turned to modern data sources, such as Internet search queries, which have been shown to be effective for monitoring influenza-like illnesses. However, few have evaluated the utility of web search query data for other diseases, especially those of high morbidity and mortality or where a vaccine may not exist. In this study, we aimed to assess whether web search queries are a viable data source for the early detection and monitoring of dengue epidemics.Methodology/Principal Findings
Bolivia, Brazil, India, Indonesia and Singapore were chosen for analysis based on available data and adequate search volume. For each country, a univariate linear model was then built by fitting a time series of the fraction of Google search query volume for specific dengue-related queries from that country against a time series of official dengue case counts for a time-frame within 2003–2010. The specific combination of queries used was chosen to maximize model fit. Spurious spikes in the data were also removed prior to model fitting. The final models, fit using a training subset of the data, were cross-validated against both the overall dataset and a holdout subset of the data. All models were found to fit the data quite well, with validation correlations ranging from 0.82 to 0.99.Conclusions/Significance
Web search query data were found to be capable of tracking dengue activity in Bolivia, Brazil, India, Indonesia and Singapore. Whereas traditional dengue data from official sources are often not available until after some substantial delay, web search query data are available in near real-time. These data represent valuable complement to assist with traditional dengue surveillance. 相似文献60.
Piriformospora indica is an axenically cultivable root endophytic fungus which exerts plant growth promoting effects on its host plants. To enable commercial production of its spores, the medium composition and culture conditions have been optimized in a 14 L bioreactor such that they result in maximum biomass during growth phase and in maximum spore yield during subsequent sporulation phase. Maximum spore yields were obtained with modified Kaefer medium using a glucose deprivation strategy. An enhancement of 100% in overall biomass productivity (0.18 g L(-1) h(-1)) and reduction of about 70% in the time (60 h) required to achieve the maximum spore yield (9.25×10(7) spores/mL) was achieved in comparison to the original Kaefer medium. The high spore yield obtained in the present study seems to be economical for commercial production of P. indica. 相似文献