| Microtubule Seeded-assembly in the Presence of Poorly Nucleating Nucleotide Analogues
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Author:
Date:
2020-08-20
[Abstract] Microtubule dynamic instability is driven by the hydrolysis of the GTP bound to the β-subunit of the α-β tubulin heterodimer. Nucleotide analogues are commonly used to mimic the different steps of the tubulin GTPase cycle, but most of them are poor microtubule nucleators. Usually, microtubule assembly is seeded by guanylyl-(α, β)-methylene-diphosphonate (GMPCPP) or glycerol that can be limiting factors in monitoring the effect of other nucleotide analogs on their polymerization. Here, we describe a protocol that allows the assembly of microtubules in the presence of nucleotide analogues without the need of heterogeneous seeds and at a low final glycerol concentration. Microtubules are first assembled in the presence of the analogue of interest and glycerol to promote assembly. These ...
[摘要] [摘要 ] 微管动态不稳定性是由与α - β 微管蛋白异二聚体的β- 亚基结合的GTP水解驱动的。核苷酸类似物通常用于模拟微管蛋白GTPase循环的不同步骤，但其中大多数是不良的微管成核剂。通常，微管组装是通过胍基-（α ，β ）-亚甲基-二膦酸酯（GMPCPP）或甘油来接种的，它们可能是限制其他核苷酸类似物对其聚合作用的监测因素。 在这里，我们描述了一种协议，该协议允许在核苷酸类似物存在的情况下组装微管，而无需异质种子，并且最终甘油浓度低。首先在感兴趣的类似物和甘油的存在下组装微管以促进组装。然后对这些微管进行超声处理，以产生种子，这些种子将在不存在甘油的情况下用于组装微管。这种策略产生了均质的核苷酸结合的微管，可以通过生化或结构方法（如冷冻电子显微镜）进一步分析。
[背景 ] 核苷酸类似物通常用于研究的构象变化，该α - β 微管组装和水解绑定到其可交换的（E）的网站上的GTP的期间微管蛋白异源二聚体经历。但是，除GMPCPP以外，大多数类似物都是微管成核剂。为克服这一困难，GMPCPP稳定化的种子通常用于存在其他类似物的情况下延长微管（Maurer 等人，2011和2014； Zhang ...
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| Manganese Superoxide Dismutase Activity Assay in the Yeast Saccharomyces cerevisiae
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Author:
Date:
2020-03-05
[Abstract] Superoxide dismutases (SODs) act as a primary defence against reactive oxygen species (ROS) by converting superoxide anion radicals (O2-) into molecular oxygen (O2) and hydrogen peroxide (H2O2). Members of this enzyme family include CuZnSODs, MnSODs, FeSODs, and NiSODs, depending on the nature of the cofactor that is required for proper activity. Most eukaryotes, including yeast, possess CuZnSOD and MnSOD. This protocol aims at assessing the activity of the yeast Saccharomyces cerevisiae MnSOD Sod2p from cellular extracts using nitroblue tetrazolium staining. This method can be used to estimate the cellular bioavailability of Mn2+ as well as to evaluate the redox state of the cell.
[摘要] [摘要 ] 超氧化物歧化酶（SOD能）充当主防御针对反应性氧物质（ROS）通过转换的超氧阴离子自由基（O 2 - ）为分子氧（O 2 ）和过氧化氢（H 2 ? 2 ）。这种酶的家庭成员包括CuZnSODs ，MnSODs ，FeSODs 和NiSODs ，这取决于是需要适当的活动辅助因子的性质。大多数真核生物，包括酵母，都具有CuZnSOD 和MnSOD 。该协议旨在评估酵母的活性 使用硝基蓝四唑染色法从细胞提取物中提取酿酒酵母MnSOD Sod2p 。该方法可用于估计Mn 2+ 的细胞生物利用度以及评估细胞的氧化还原状态。
[背景 ] 的SODs被定义为减少正常有氧代谢为氧气和过氧化氢期间形成的氧的有害自由基含金属的抗氧化剂酶。：这些酶是基于需要作为辅因子进行适当的酶活性的金属分类CuZnSODs ，MnSODs ，FeSODs ，和NiSODs 。在酿酒酵母中，有两个S OD ：CuZn-Sod1p和Mn-Sod2p（Abreu和Cabelli ...
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| Isolation of Chromatin-bound Proteins from Subcellular Fractions for Biochemical Analysis
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Author:
Date:
2018-10-05
[Abstract] Shuttling of proteins between different cellular compartments controls their proteostasis and can contribute in some cases to regulate their activity. Biochemical analysis of chromatin-bound proteins, such as transcription factors, is often difficult because of their low yield and due to the interference from nucleic acids. This protocol describes a method to efficiently fractionate cells combined with a mechanical (i.e., sonication) or an enzymatic treatment (i.e., benzonase) that facilitates analysis of chromatin-bound protein extracts by Western blot analysis or by protein pull-down assays. This approach can be valuable to enrich a particular protein within a particular subcellular fraction either to study specific post-translational modification patterns or to ...
[摘要] 在不同细胞区室之间穿梭蛋白质控制它们的蛋白质稳态，并且在某些情况下可以有助于调节它们的活性。 染色质结合蛋白（例如转录因子）的生化分析通常是困难的，因为它们的产率低并且由于核酸的干扰。 该协议描述了一种有效分离细胞的方法，结合机械（即，超声处理）或酶处理（即，benzonase），有助于分析染色质结合蛋白提取物 通过蛋白质印迹分析或蛋白质下拉分析。 该方法对于富集特定亚细胞级分内的特定蛋白质以研究特定的翻译后修饰模式或鉴定特定的蛋白质 - 蛋白质相互作用可能是有价值的。
【背景】许多染色质结合蛋白的活性和翻译后调节研究很少，因为在分离它们进行生化分析时存在技术困难。这甚至是转录因子的情况，例如基本的螺旋 - 环 - 螺旋（bHLH）转录因子，其通常在组织或细胞模型中具有稀缺的时间和空间表达模式（Dennis 等。，2018）。当生物材料的量成为研究分子途径的障碍时，协议细化有助于解除技术限制（Gillotin和Guillemot，2016）。在我们最近的研究中，我们努力了解神经元bHLH转录因子Ascl1的蛋白水解是如何在神经元分化的细胞模型中调节的（Gillotin et ...
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