• Title/Summary/Keyword: Shuttle

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Lactate: a multifunctional signaling molecule

  • Lee, Tae-Yoon
    • Journal of Yeungnam Medical Science
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    • v.38 no.3
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    • pp.183-193
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    • 2021
  • Since its discovery in 1780, lactate has long been misunderstood as a waste by-product of anaerobic glycolysis with multiple deleterious effects. Owing to the lactate shuttle concept introduced in the early 1980s, a paradigm shift began to occur. Increasing evidence indicates that lactate is a coordinator of whole-body metabolism. Lactate is not only a readily accessible fuel that is shuttled throughout the body but also a metabolic buffer that bridges glycolysis and oxidative phosphorylation between cells and intracellular compartments. Lactate also acts as a multifunctional signaling molecule through receptors expressed in various cells and tissues, resulting in diverse biological consequences including decreased lipolysis, immune regulation, anti-inflammation, wound healing, and enhanced exercise performance in association with the gut microbiome. Furthermore, lactate contributes to epigenetic gene regulation by lactylating lysine residues of histones, accounting for its key role in immune modulation and maintenance of homeostasis.

Longitudinal Modal Analysis of a LOX-filled Tank Using the Virtual Mass Method

  • Lee, SangGu;Sim, JiSoo;Shin, SangJoon;Kim, Youdan
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.4
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    • pp.807-815
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    • 2017
  • For liquid rocket engine(LRE)-based space launch vehicles, longitudinal instability, often referred to as the pogo phenomenon in the literature is predicted. In the building block of system-level task, accurate dynamic modeling of a fluid-filled tank is an essential. This paper attempts to apply the virtual mass method that accounts for the interaction of the vehicle structure and the enclosed liquid oxygen to LOX-filled tanks. The virtual mass method is applied in a modal analysis considering the hydroelastic effect of the launch vehicle tank. This method involves an analysis of the fluid in the tank in the form of mass matrix. To verify the accuracy of this method, the experimental modal data of a small hemispherical tank is used. Finally, the virtual mass method is applied to a 1/8-scale space shuttle external tank. In addition, the LOX tank bottom pressure in the external tank model is estimated. The LOX tank bottom pressure is the factor required for the coupling of the LOX tank with the propulsion system. The small hemispherical tank analysis provides relatively accurate results, and the 1/8-scale space shuttle external tank provides reasonable results. The LOX tank bottom pressure is also similar to that in the numerical results of a previous analysis.

Expression of the Bacillus stearothermophilus NO2 CGTase gene in Saccharomyces cerevisiae (Saccharomyces cerevisiae 내에서 Bacillus stearothermophilus NO2 CGTnse 유전자의 발현)

  • 유동주;박현이;전숭종;권현주;남수완;김병우
    • Microbiology and Biotechnology Letters
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    • v.30 no.3
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    • pp.206-209
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    • 2002
  • For the expression of CGTase gene(cgtS) kom Bacillus stearothemophilus NO2 in Saccharomyces cerevisiae, cgtS gene was subcloned into the Eschepichia coll-yeast shuttle vector, pVT103-U. The constructed plasmid, pVT-CGTS was introduced to 5. cemi-siae 2805 cell, and then the cgtS gene under the control of adhl promoter was successfully expressed in the yeast transformant and 87% of the total activity was detected into the fermentation medium. Therefore, the signal peptide of B. stearothemephilus NO2 CeTase showed high secretion efficiency in 5. cerevisiae. Optimal conditions of the recombinant yeast cell f3r expression of CGTase was achieved, when 5. cerevisiae 2805/pv7-CGTS was cultivated on YP medium at 2% dextrose, pH 5.5,$30^{\circ}C$ and the expression level of CGTase was 0.624units/mL for 48 h culture.

Construction of a Corynebacteriurn glutarnicum-Escherichicr coli Shuttle Vector and Cloning the Homoserine ehydrogenase Gene from C. glutamicum (Corynebacterium glutamicum-Escherichia coli Shuttle Vector 개발과 C.glutamicum 의 Homoserine Dehydrogenase Gene Cloning)

  • 최신건;박종현;신현경
    • Microbiology and Biotechnology Letters
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    • v.19 no.1
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    • pp.31-36
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    • 1991
  • A 7.5 kilobases hybrid plasmid, designated as pCE1301, was constructed by combining Eschurichia cwli plasmid pBELl which carries the kanamycin resistance gene of Tn5 with a cryptic plasmid, pSRl of Corynebacterium glutamicum. pCE1301 was transformed C. glutaicum by PEG-mediated protoplast method and its transformation efficiency was about $3.0\times 10^3$ transformants per $\mu g$ of the hybrid plasmid DNA. The physical map reveals that pCE1301 has single restriction sites for SalI and EcoRl, respectively. 'The kanamycin resistance of pCE1301 was stably maintained in C. glutamicum up to 25 generations and any segregation was not detected. pCI31301 was also introduced into Brevibacterium flavum and E coil, and replicated in those strains. pCE1301 was proved to be useiul in cloning the homoscrine dehydrogenase gene from C. glutamicum.

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Construction of Plasmid Vectors for Zymomonas mobilis (Zymomonas mobilis의 Plasmid Vector 제조에 관한 연구)

  • Hwang, Duk-Ju;Rhee, Sang-Ki;Pack, Moo-Young
    • Microbiology and Biotechnology Letters
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    • v.15 no.5
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    • pp.319-327
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    • 1987
  • In order to develop useful plasmid vectors for Zymomonas cells, attempts were made to isolate natural plasmids from Z. mobilis ATCC10988. Among a few plasmids isolated, a small plasmid of 3.9 Kb size was chosen and designated as pZM3. By introducing the replication origin of pZM3 into pBR325, a hybrid plasmid vector of 8.4 Kb size, pHZ22, was constructed. This vector contained chloramphenicol resistant gene as a selectable marker and proved to be conjugally transmissible and stably maintained in Z. mobilis. Tetracycline resistant gene was isolated from RP4 and introduced into pHZ22 to make a new vector called pHZT224 of 10.7 Kb size. Through n series of experiments, it was evident that these plasmid vectors containing selectable markers of chloramphenicol and tetracycline resistance were shuttle vectors functional in Z. mobilis as well as E. coli.

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