| Determination of Hydrodynamic Radius of Proteins by Size Exclusion Chromatography
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Author:
Date:
2017-04-20
[Abstract] Size exclusion chromatography (SEC) or gel filtration is a hydrodynamic technique that separates molecules in solution as a function of their size and shape. In the case of proteins, the hydrodynamic value that can be experimentally derived is the Stokes radius (Rs), which is the radius of a sphere with the same hydrodynamic properties (i.e., frictional coefficient) as the biomolecule. Determination of Rs by SEC has been widely used to monitor conformational changes induced by the binding of calcium (Ca2+) to many Ca2+-sensor proteins. For this class of proteins, SEC separation is based not just on the variation in protein size following Ca2+ binding, but likely arises from changes in the hydration shell structure.
This ...
[摘要] 尺寸排阻色谱法（SEC）或凝胶过滤是一种流体动力学技术，它将溶液中的分子作为其尺寸和形状的函数。在蛋白质的情况下，可以通过实验得出的流体动力学值是斯托克斯半径（R s），它是具有相同流体力学性质的球体的半径（即， >摩擦系数）作为生物分子。通过SEC测定R s已经被广泛用于监测由钙（Ca 2+）与许多Ca 2+连接引起的构象变化传感器蛋白。对于这类蛋白质，SEC分离不仅基于Ca 2 + 结合后的蛋白质尺寸变化，而且可能来自水合壳结构的变化。
该方案旨在使用快速蛋白质液相色谱（FPLC）系统对预填充柱进行凝胶过滤实验，以确定蛋白质的R 1，其中一些适用于Ca 2 + 传感器蛋白。
凝胶过滤基于其相对的能力分离不同大小和形状的分子，以穿透具有明确孔径的多孔珠床，其识别分馏范围。大于完全排除进入孔隙的分馏范围的分子快速流过色谱柱，首先以空间体积（V 0 O）（其为支持颗粒外的间隙体积）洗脱。能够扩散到珠的孔中的小于分级范围的分子具有可用于流动相的总体积，因此它们更缓慢地移动通过床并最后洗脱。具有中等维度的分子将以包含在流动相可利用的空隙体积和总体积之间的洗脱体积（V e e e e）被洗脱（分子越小，其进入孔隙越大矩阵，因此其V e e越大）。
蛋白质的分子量可以通过比较其洗脱体积参数K ...
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| In vivo OVA-specific Cytotoxic CD8+ T Cell Killing Assay
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Author:
Date:
2016-06-20
[Abstract] Cytotoxic CD8+ T cells are responsible for the lysis of cells expressing peptides associated with MHC class I molecules and derived from infection with a pathogen or from mutated antigens. In order to quantify in vivo this antigen-specific CD8+ T cell killing activity, we use the in vivo killing assay (IVK). Here we describe the protocol for the lysis of cells expressing a CD8+ T cell epitope of the OVA protein (SIINFEKL). Mice are previously immunized with the OVA protein and 7 days after immunization, they receive a mix of target cells, prepared from naive C57BL/6 spleen cells pulsed with the SIINFEKL peptide and labeled with high level of CFSE and of non-pulsed control cells labeled with low level of CFSE. One day later, the spleen ...
[摘要] 细胞毒性CD8 + T细胞负责裂解表达与MHC I类分子相关并且源自病原体感染或突变抗原的肽的细胞。为了在体内定量该抗原特异性CD8 + T细胞杀伤活性，我们使用体内杀伤试验（IVK）。在这里，我们描述了用于裂解表达OVA蛋白（SIINFEKL）的CD8 + T细胞表位的细胞的方案。小鼠先前用OVA蛋白免疫，并且在免疫后7天，它们接受从用SIINFEKL肽脉冲并用高水平的CFSE标记的天然C57BL/6脾细胞制备的靶细胞和标记的非脉冲对照细胞的混合物具有低水平的CFSE。一天后，分离受体小鼠的脾细胞并通过FACS分析以测量CFSE高度细胞和CFSE低度细胞的量。通过在免疫的和未免疫的小鼠中CFSE高与低之间的差计算裂解的百分比。
测量抗原特异性CD8 + T细胞在体内裂解其抗原的能力对评价诱导针对病原体或肿瘤抗原的适应性细胞毒性应答是非常重要的。
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| Allergen Sensitization and Challenge to Ovalbumin
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Author:
Date:
2013-04-05
[Abstract] This protocol describes the sensitization and challenge of mice with ovalbumin for use as an acute murine model of asthma. This protocol induces reproducible airway inflammation and remodelling, and bronchial hyperresponsiveness to methacholine as measured by barometric plethysmography, as well as by the Flexivent® technique in Balb/c mice.
[摘要] 该协议描述了用卵清蛋白作为哮喘的急性鼠模型的小鼠的致敏和攻击。 该协议诱导可重复的气道炎症和重塑，以及通过气压体积描记术以及通过Flexb/c小鼠中的Flexivent 技术测量的对乙酰甲胆碱的支气管高反应性。
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