| Quantification of Protein Kinase A (PKA) Activity by An in vitro Radioactive Assay Using the Mouse Sperm Derived Enzyme
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Author:
Date:
2020-06-20
[Abstract] In order to acquire fertilizing potential, mammalian sperm must undergo a process known as capacitation, which relies on the early activation of Protein Kinase A (PKA). Frequently, PKA activity is assessed in whole-cell experiments by analyzing the phosphorylation status of its substrates in a western-blot. This technique faces two main disadvantages: it is not a direct measure of the kinase activity and it is a time-consuming approach. However, since PKA can be readily obtained from sperm extracts, in vitro assays such as the “radioactive assay” can be performed using the native enzyme. Unlike western-blot, the radioactive assay is a straightforward technique to evaluate PKA activity by quantification of incorporated 32P into a peptidic ...
[摘要] [Abstract]为了获得受精潜能，哺乳动物的精子必须经历一个被称为电容的过程，这个过程依赖于蛋白激酶A（PKA）的早期激活。通常，在全细胞实验中，通过分析其底物在western-blot中的磷酸化状态来评估PKA的活性。这种技术面临着两个主要的缺点：它不是对激酶活性的直接测量，而且是一种耗时的方法。然而，由于PKA可以很容易地从精子提取物中获得，体外检测如"放射性检测"可以使用原生酶进行。与western-blot不同的是，放射性测定法是一种直接的技术，通过将整合的32P定量到肽类底物中来评价PKA的活性。这种方法很容易允许分析PKA的不同激动剂或拮抗剂。由于小鼠精子是可溶性PKA的丰富来源，这种测定法可以进行简单的分馏，使PKA既可用于体外测试药物对PKA活性的影响，也可用于跟踪PKA活性在增容开始时的变化。
[Background] ...
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| In vivo and in vitro 31P-NMR Study of the Phosphate Transport and Polyphosphate Metabolism in Hebeloma cylindrosporum in Response to Plant Roots Signals
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Author:
Date:
2018-08-20
[Abstract] We used in vivo and in vitro phosphorus-31 nuclear magnetic resonance (31P-NMR) spectroscopy to follow the change in transport, compartmentation and metabolism of phosphate in the ectomycorrhizal fungus Hebeloma cylindrosporum in response to root signals originating from host (Pinus pinaster) or non-host (Zea mays) plants. A device was developed for the in vivo studies allowing the circulation of a continuously oxygenated mineral solution in an NMR tube containing the mycelia. The in vitro studies were performed on fungal material after several consecutive treatment steps (freezing in liquid nitrogen; crushing with perchloric acid; elimination of perchloric acid; freeze-drying; dissolution in an appropriate liquid ...
[摘要] 我们使用体内和体外磷-31核磁共振（ 31 P-NMR）光谱来跟踪运输，分区和 外生菌根真菌 Hebeloma cylindrosporum 中的磷酸盐代谢响应来自宿主（ Pinus pinaster ）或非宿主（ Zea mays ）的根信号植物。 开发了一种用于体内研究的装置，其允许连续氧化的矿物质溶液在含有菌丝体的NMR管中循环。 在几个连续的处理步骤（在液氮中冷冻;用高氯酸压碎;消除高氯酸;冷冻干燥;在适当的液体培养基中溶解）后，对真菌材料进行体外研究。
【背景】 菌根真菌和植物之间的关联改善了宿主植物的P营养（Smith和Read，2008; Plassard和Dell，2010; Cairney，2011; Smith 等人，，2015）。这种积极效应主要归因于真菌菌丝对磷酸盐（Pi）的吸收，探测了在活跃吸收根周围的耗竭区以外的大量土壤（Smith和Read，2008; Cairney，2011; Smith et al。< em="">，2015）和真菌细胞分泌细胞外磷酸酶（Quiquampoix和Mousain，2005）。吸收的Pi部分地掺入磷酸化的代谢物，磷脂和核酸中，并且部分地浓缩成多磷酸盐（PolyP），其中它们构成液泡中的储存池（Ashford 等人，，1994）。该协议详述了一种装置，该装置允许通过 31 ...
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| Preparation of Cerebellum Granule Neurons from Mouse or Rat Pups and Evaluation of Clostridial Neurotoxin Activity and Their Inhibitors by Western Blot and Immunohistochemistry
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Author:
Date:
2018-07-05
[Abstract] Cerebellar Granule Neurons (CGN) from post-natal rodents have been widely used as a model to study neuronal development, physiology and pathology. CGN cultured in vitro maintain the same features displayed in vivo by mature cerebellar granule cells, including the development of a dense neuritic network, neuronal activity, neurotransmitter release and the expression of neuronal protein markers. Moreover, CGN represent a convenient model for the study of Clostridial Neurotoxins (CNT), most notably known as Tetanus and Botulinum neurotoxins, as they abundantly express both CNT receptors and intraneuronal substrates, i.e., Soluble N-ethylmaleimide-sensitive factor activating protein receptors (SNARE proteins). Here, we describe a protocol for obtaining a highly pure ...
[摘要] 来自产后啮齿动物的小脑颗粒神经元（CGN）已被广泛用作研究神经元发育，生理学和病理学的模型。 CGN体外培养维持成熟小脑颗粒细胞在体内显示的相同特征，包括发育致密的神经炎网络，神经元活动，神经递质释放和神经元的表达 蛋白质标记。 此外，CGN代表了梭菌神经毒素（CNT）研究的便利模型，最着名的是破伤风和肉毒杆菌神经毒素，因为它们大量表达CNT受体和神经元内基质， ie ，可溶性N-乙基马来酰亚胺 - 敏感因子激活蛋白受体（SNARE蛋白）。 在这里，我们描述了从出生后大鼠/小鼠获得高纯度CGN培养物的方案和用CNT中毒的简便方法。 我们还说明了评估CNT活性及其抑制的方便方法。
【背景】梭菌神经毒素（CNT）的大家族由破伤风神经毒素（TeNT）和肉毒杆菌神经毒素（BoNT）的多种变体形成，它们分别是破伤风和肉毒中毒的神经麻痹毒素（Schiavo et al。，2000; Johnson和Montecucco，2008; Rossetto et al。，2014）。 TeNT，七种BoNT血清型（BoNT / A至/ G）及其许多亚型是金属蛋白酶，通过切割SNARE蛋白（可溶性N-乙基马来酰亚胺敏感因子激活蛋白受体），三种必需蛋白质来阻断神经递质的释放而引起神经麻痹。控制突触小泡与突触前质膜的融合（Rossetto et al。，2014; ...
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