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Search Results: 1 - 10 of 3014 matches for " trehalose synthetic pathway "
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Cloning, expression and functional analysis of the genes in TPS/TPP trehalose synthetic pathway of Meiothermus ruber

Yueming Zhu,Yichen Tang,Hengyi Xu,Juan Zhang,Dongsheng Wei,Laijun Xing,Mingchun Li,

生物工程学报 , 2009,
Abstract: By constructing the genomic DNA library of Meiothermus ruber CBS-01, the genes of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) involved in trehalose synthesis were cloned. The genes were cloned into the plasmid pET21a, and expressed in Escherichia coli Rosetta gami (DE3). The activities of these two purified enzymes were confirmed by thin layer chromatography (TLC). Meanwhile, we tested the cellular compatible solutes of M. ruber CBS-01 under different environmental pressure,...
Cell-to-cell communication circuits: quantitative analysis of synthetic logic gates
Marta Hoffman-Sommer,Edda Klipp
Frontiers in Physiology , 2012, DOI: 10.3389/fphys.2012.00287
Abstract: One of the goals in the field of synthetic biology is the construction of cellular computation devices that could function in a manner similar to electronic circuits. To this end, attempts are made to create biological systems that function as logic gates. In this work we present a theoretical quantitative analysis of a synthetic cellular logic-gates system, which has been implemented in cells of the yeast Saccharomyces cerevisiae (Regot et al., 2011). It exploits endogenous MAP kinase signaling pathways. The novelty of the system lies in the compartmentalization of the circuit where all basic logic gates are implemented in independent single cells that can then be cultured together to perform complex logic functions. We have constructed kinetic models of the multicellular IDENTITY, NOT, OR, and IMPLIES logic gates, using both deterministic and stochastic frameworks. All necessary model parameters are taken from literature or estimated based on published kinetic data, in such a way that the resulting models correctly capture important dynamic features of the included mitogen-activated protein kinase pathways. We analyze the models in terms of parameter sensitivity and we discuss possible ways of optimizing the system, e.g., by tuning the culture density. We apply a stochastic modeling approach, which simulates the behavior of whole populations of cells and allows us to investigate the noise generated in the system; we find that the gene expression units are the major sources of noise. Finally, the model is used for the design of system modifications: we show how the current system could be transformed to operate on three discrete values.
Importancia da logística da via de síntese em Química Verde
Machado, Adélio A. S. C;
Química Nova , 2011, DOI: 10.1590/S0100-40422011000700032
Abstract: the role of the logistics in the design of synthetic pathways aimed at greenish is discussed. the influence on costs (of reagents, solvents and total), as well as on atomic productivity green metrics (atomic economy and e factor), of the position along the pathway of a step with low yield, or involving high dilution of the reagents or expensive reagents, has been evaluated by calculations on a linear pathway model. the results show the economic importance of green chemistry and provide useful information for pathway design or improvement.
Preparation and Properties of Polyaniline in the Presence of Trehalose  [PDF]
Hirotsugu Kawashima, Hiromasa Goto
Soft Nanoscience Letters (SNL) , 2011, DOI: 10.4236/snl.2011.13013
Abstract: Oxidative polymerization of aniline in aqueous solution in the presence of trehalose was conducted. Fourier transform infrared spectroscopy confirmed successful preparation of polyaniline containing a trace amount of trehalose. Electron spin resonance spectroscopy revealed that electron spin concentration of the polyaniline increases with aniline/trehalose ratio in the polymerization. Scanning electron microscopy revealed that the polyaniline shows granular and porous morphology. Electrical conductivity of these polyanilines was in the order of 10-4 S/cm.
Development of Small Molecules Activating TRAIL Apoptosis Pathway for Cancer Therapies  [PDF]
Anita C. Bellail, Chunhai Hao
Open Journal of Apoptosis (OJApo) , 2013, DOI: 10.4236/ojapo.2013.24008
Abstract: Development of Small Molecules Activating TRAIL Apoptosis Pathway for Cancer Therapies
Measuring Solution Viscosity and its Effect on Enzyme Activity
Uribe Salvador,Sampedro José G.
Biological Procedures Online , 2003, DOI: 10.1251/bpo52
Abstract: In proteins, some processes require conformational changes involving structural domain diffusion. Among these processes are protein folding, unfolding and enzyme catalysis. During catalysis some enzymes undergo large conformational changes as they progress through the catalytic cycle. According to Kramers theory, solvent viscosity results in friction against proteins in solution, and this should result in decreased motion, inhibiting catalysis in motile enzymes. Solution viscosity was increased by adding increasing concentrations of glycerol, sucrose and trehalose, resulting in a decrease in the reaction rate of the H+-ATPase from the plasma membrane of Kluyveromyces lactis. A direct correlation was found between viscosity (&eegr;) and the inhibition of the maximum rate of catalysis (V max). The protocol used to measure viscosity by means of a falling ball type viscometer is described, together with the determination of enzyme kinetics and the application of Kramers’ equation to evaluate the effect of viscosity on the rate of ATP hydrolysis by the H+-ATPase.
Cofactor Engineering for Enhancing the Flux of Metabolic Pathways
M. Kalim Akhtar,Patrik R. Jones
Frontiers in Bioengineering and Biotechnology , 2014, DOI: 10.3389/fbioe.2014.00030
Abstract: The manufacture of a diverse array of chemicals is now possible with biologically engineered strains, an approach that is greatly facilitated by the emergence of synthetic biology. This is principally achieved through pathway engineering in which enzyme activities are coordinated within a genetically amenable host to generate the product of interest. A great deal of attention is typically given to the quantitative levels of the enzymes with little regard to their overall qualitative states. This highly constrained approach fails to consider other factors that may be necessary for enzyme functionality. In particular, enzymes with physically bound cofactors, otherwise known as holoenzymes, require careful evaluation. Herein, we discuss the importance of cofactors for biocatalytic processes and show with empirical examples why the synthesis and integration of cofactors for the formation of holoenzymes warrant a great deal of attention within the context of pathway engineering.
Optimization of the IPP Precursor Supply for the Production of Lycopene, Decaprenoxanthin and Astaxanthin by Corynebacterium glutamicum
Sabine A. E. Heider,Volker F. Wendisch
Frontiers in Bioengineering and Biotechnology , 2014, DOI: 10.3389/fbioe.2014.00028
Abstract: The biotechnologically relevant bacterium Corynebacterium glutamicum, currently used for the million ton-scale production of amino acids for the food and feed industries, is pigmented due to synthesis of the rare cyclic C50 carotenoid decaprenoxanthin and its glucosides. The precursors of carotenoid biosynthesis, isopenthenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate, are synthesized in this organism via the methylerythritol phosphate (MEP) or non-mevalonate pathway. Terminal pathway engineering in recombinant C. glutamicum permitted the production of various non-native C50 and C40 carotenoids. Here, the role of engineering isoprenoid precursor supply for lycopene production by C. glutamicum was characterized. Overexpression of dxs encoding the enzyme that catalyzes the first committed step of the MEP-pathway by chromosomal promoter exchange in a prophage-cured, genome-reduced C. glutamicum strain improved lycopene formation. Similarly, an increased IPP supply was achieved by chromosomal integration of two artificial operons comprising MEP pathway genes under the control of a constitutive promoter. Combined overexpression of dxs and the other six MEP pathways genes in C. glutamicum strain LYC3-MEP was not synergistic with respect to improving lycopene accumulation. Based on C. glutamicum strain LYC3-MEP, astaxanthin could be produced in the milligrams per gram cell dry weight range when the endogenous genes crtE, crtB, and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were coexpressed with the genes for lycopene cyclase and β-carotene hydroxylase from Pantoea ananatis and carotene C(4) oxygenase from Brevundimonas aurantiaca.
Synthetic Biology: Applying Engineering to Life Sciences to Develop Rationally Designed Biological Parts, Devices, and Systems
Ianis G. Matsoukas
Frontiers in Bioengineering and Biotechnology , 2013, DOI: 10.3389/fbioe.2013.00008
S-adenosyl-L-methionine, trehalose and oleanolic acid in few plants  [PDF]
Dipankar Malakar, Paramita Chaudhuri, Trina Dutta, Anil K Ghosh
Health (Health) , 2010, DOI: 10.4236/health.2010.28144
Abstract: S-Adenosyl-L-Methionine (AdoMet), S-Adenosyl- L-Homocysteine (AdoHcy), adenosine, trehalose and oleanolic acid were measured in six medicinal herbs and three spices. The findings showed that AdoMet content was forty six fold higher in the leaves of Catharanthus roseus as compared with average AdoMet content of rest of the plants. In comparison to other plants, Withania somnifera had very high AdoHcy: Ado-Met and adenosine: AdoMet ratios indicating it may have contained high AdoMet. Trehalose was found to be twenty fold and nine fold higher in bulb of Allium cepa and root of Withania somnifera respectively with respect to average trehalose content of rest of the plants. Ocimum sanctum appeared to be a rich source of oleanolic acid. It appeared from our study that Catharanthus roseus, Allium cepa and Ocimum sanctum could be utilized as natural sources of AdoMet, trehalose and oleanolic acid respectively.
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