| Total Triglyceride Quantification in Caenorhabditis elegans
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Author:
Date:
2020-11-20
[Abstract] Several studies suggest an important role of lipid metabolism in regulating longevity of Caenorhabditis elegans. Therefore, assays to quantify lipids have enormous value in understanding aging and pathologies associated with it. Approximately 70% of lipid metabolism genes in the nematode have orthologs in humans. Amenability of C. elegans to genetic manipulations has allowed investigations into the role of specific genetic factors in lipid metabolism. Here, we describe a protocol to quantify total triglycerides in C. elegans, which can be extended to studies of the effects of altered environmental and genetic factors on stored fats. This protocol quantifies the picomoles of the triglycerides, in whole worm lysate. Due to the sensitivity of the assay, it could ...
[摘要] [摘要]多项研究表明脂质代谢在调节秀丽隐杆线虫的寿命中具有重要作用。因此，定量脂质的测定在理解衰老和与其相关的病理学方面具有巨大价值。线虫中大约70％的脂质代谢基因在人类中具有直系同源物。秀丽隐杆线虫对基因操作的适应性允许调查特定遗传因素在脂质代谢中的作用。在这里，我们描述了一个协议，以定量总甘油三酯在秀丽隐杆线虫，这CA n可以扩展到环境和遗传因素改变对储存脂肪的影响的研究。该协议量化了整个蠕虫裂解物中甘油三酸酯的皮摩尔。由于测定的敏感性，它可以帮助鉴定总存储脂肪的细微变化，这是显微镜技术无法识别的。
[背景]多余的卡路里通常以三酰基甘油或糖原的形式存储（Cohen，2018年）。甘油三酸酯（TAGs）的异常水平与人类的心脏病，胰腺炎和动脉粥样硬化有关（Cameron等人，1974; Lee等人，2003; Walther和Farese，2012; Onal等人，2017）。TAG被包装到细胞质中的脂滴中。脂质液滴存在于真核细胞中，大小从20 nm到100 µm不等（Stobart等，1986； ...
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| The ATPase Activity of Escherichia coli Expressed AAA+-ATPase Protein
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Author:
Date:
2020-08-05
[Abstract] ATPases are the enzymes that breakdown ATP to ADP and release inorganic phosphate (Pi). Here we provide a detailed protocol to determine the ATPase activity of a recombinant AAA+-ATPase protein (GENERAL CONTROL NON-REPRESSIBLE-4 [GCN4]) by spectrophotometric absorption at 360 nm to measure the accumulated inorganic phosphate. In general, the substrate 2-amino-6-mercapto-7-methylpurine riboside (methylthioguanosine, a guanosine analog: MESG) is enzymatically converted in the presence of Pi by purine nucleoside phosphorylase (PNP) to ribose 1-phosphate and 2-amino-6-mercapto-7-methylpurine. The spectrophotometric shift in maximum absorbance at 330 nm for the MESG substrate and subsequent conversion product at 360 nm due to enzymatic conversion was measured. The GCN4-His-tagged ...
[摘要] [摘要]ATP酶是将ATP分解为ADP并释放无机磷（Pi）的酶。在这里，我们提供了一个详细的方案来测定重组AAA+-ATPase蛋白（一般对照非抑制-4[GCN4]）的ATPase活性，在360nm处测定无机磷的累积量。一般而言，底物2-氨基-6-巯基-7-甲基嘌呤核苷（甲基硫代鸟苷，鸟苷类似物：MESG）在Pi存在下通过嘌呤核苷磷酸化酶（PNP）酶转化为核糖1-磷酸和2-氨基-6-巯基-7-甲基嘌呤。测量了由于酶转化而导致的MESG底物和随后的转化产物在330nm处的最大吸收度的分光光度偏移。将gcn4his标记的重组蛋白在大肠杆菌BL21细胞中表达，并用Ni-NTA柱纯化。将纯化后的蛋白质用于溶液中Pi的定量测定或连续测定由于GCN4的atp酶活性而释放的Pi，GCN4是一种在许多真核生物中保存的AAA+-ATPase蛋白，在植物受到生物和非生物胁迫时调节气孔开度。
[背景] ...
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| Production, Purification and Characterization of Recombinant Biotinylated Phytochrome B for Extracellular Optogenetics
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Author:
Date:
2020-03-05
[Abstract] In the field of extracellular optogenetics, photoreceptors are applied outside of cells to obtain systems with a desired functionality. Among the diverse applied photoreceptors, phytochromes are the only ones that can be actively and reversibly switched between the active and inactive photostate by the illumination with cell-compatible red and far-red light. In this protocol, we describe the production of a biotinylated variant of the photosensory domain of A. thaliana phytochrome B (PhyB-AviTag) in E. coli with a single, optimized expression plasmid. We give detailed instructions for the purification of the protein by immobilized metal affinity chromatography and the characterization of the protein in terms of purity, biotinylation, spectral photoswitching and the ...
[摘要] [摘要 ] 在细胞外光遗传学领域，光感受器被应用于细胞外，以获得具有所需功能的系统。在各种应用的感光体中，植物色素是唯一可以通过与细胞相容的红色和远红外光照射而在活性和非活性光态之间主动和可逆地切换的色素。在此协议中，我们描述了在大肠杆菌中拟南芥光敏色素B（PhyB-AviTag ）的光敏域的生物素化变体的生产。 带有一个优化的表达质粒。我们给出了通过固定的金属亲和色谱法纯化蛋白质的详细说明，并根据纯度，生物素化，光谱光开关以及与它的相互作用伴侣PIF6的光依赖性相互作用对蛋白质进行了表征。与以前使用PhyB-AviTag 进行的研究相比，此方案中使用的优化表达质粒简化了生产过程，并显示出更高的产量和纯度。
[背景 ] 在新兴的细胞外光遗传学领域，光感受器被应用于细胞外，例如，以控制生物功能或设计光响应性生物材料（Leung 等，2008；Zhang 等，2015；Chen and Wegner ，2017 ; Lyu 等人，2017 ; Wang 等人，2017 ; Bartelt 等人，2018 ; Beyer 等人，2018a ; Beyer 等人，2018b ; Jia 等人，2018 ; Kolar 等人， 2018 ; Liu 等人，2018 ; Wu 等人，2018 ; Baaske 等人，2019 ; Gil 等人，2019 ; H?rner ...
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