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Tris Base (White Crystals or Crystalline Powder/Molecular Biology), Fisher BioReagents

Company: Fisher Scientific
Catalog#: BP152-5
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Extraction and Quantification of Polyphosphate (polyP) from Gram-negative Bacteria
Author:
Date:
2018-09-20
[Abstract]  Polyphosphate (polyP), a universally conserved biomolecule, is composed of up to 1,000 phosphate monomers linked via phosphoanhydride bonds. Reaching levels in bacteria that are in the high nmoles per mg protein range, polyP plays important roles in biofilm formation and colonization, general stress protection and virulence. Various protocols for the detection of polyP in bacteria have been reported. These methods primarily differ in the ways that polyP is extracted and/or detected. Here, we report an improved method, in which we combine polyP extraction via binding to glassmilk with a very sensitive PolyP kinase/luciferase-based detection system. By using this procedure, we significantly enhanced the sensitivity of polyP detection, making it potentially applicable for mammalian tissues. [摘要]  多磷酸盐(polyP)是一种普遍保守的生物分子,由多达1,000个通过磷酸酐键连接的磷酸盐单体组成。 达到每毫克蛋白质高纳摩尔细菌的水平,polyP在生物膜形成和定植,一般应力保护和毒力中起重要作用。 已经报道了用于检测细菌中polyP的各种方案。 这些方法主要在于提取和/或检测polyP的方式不同。 在这里,我们报告了一种改进的方法,其中我们结合polyP提取通过结合到玻璃奶与非常敏感的PolyP激酶/荧光素酶检测系统。 通过使用该程序,我们显着增强了polyP检测的灵敏度,使其可能适用于哺乳动物组织。

【背景】聚磷酸盐(polyP)是一种由多达1,000种无机磷酸盐单体的直链组成的生物聚合物,存在于生命的所有三个领域的细胞中。然而,细菌是唯一已经充分研究了polyP代谢酶的生物。将ATP转化为polyP的细菌polyP激酶(PPK)催化正向和反向反应。虽然polyP的合成显然是细胞中有利的反应,但通过在体外提供足够量的ADP ,该酶可用于从polyP产生ATP,使得基于荧光素酶的ATP检测成为可能(Ault -Riché et al。,1998)。缺乏PPK的细菌在生物膜形成,运动性,持久性和各种应激反应方面存在缺陷,并显示出对次卤酸(即,漂白)应激或磷酸盐饥饿的显着增加的敏感性(图1)(Rao et al。,2009; Gray et ...

Retroviral Capsid Core Stability Assay
Author:
Date:
2018-09-20
[Abstract]  Structural stability of the capsid core is a critical parameter for the productive infection of a cell by a retrovirus. Compromised stability can lead to premature core disassembly, exposure of replication intermediates to cytosolic nucleic acid sensors that can trigger innate antiviral responses, and failure to integrate the proviral genome into the host DNA. Thus, core stability is a critical feature of viral replicative fitness. While there are several well-described techniques to assess viral capsid core stability, most are generally time and labor intensive. Recently, our group compared the relative stability of murine leukemia virus capsid cores using an in vitro detergent-based approach combined with ultracentrifugation against the popular fate of capsid assay. We found ... [摘要]  衣壳核心的结构稳定性是逆转录病毒对细胞的生产性感染的关键参数。受损的稳定性可导致核心过早解体,将复制中间体暴露于细胞溶质核酸传感器,其可触发先天的抗病毒反应,并且不能将原病毒基因组整合到宿主DNA中。因此,核心稳定性是病毒复制适应性的关键特征。虽然有几种充分描述的技术来评估病毒衣壳核心稳定性,但大多数通常是时间和劳动密集型的。最近,我们小组使用基于体外洗涤剂的方法结合超速离心法对衣壳测定的流行命运比较了鼠白血病病毒衣壳核心的相对稳定性。我们发现两种方法都得出了类似的结论,尽管第一种方法是比较显示核心稳定性差异的病毒突变体时评估相对衣壳核心稳定性的一种非常简单和快速的方法。

【背景】逆转录病毒已经进化出复制周期,在规避宿主抗病毒反应方面表现优异。逆转录病毒开发的一种策略是将其复制中间体与胞质核酸传感器如cGAS,TREX1,IFI203和DDX41屏蔽起来(Yan et al。,2010; Gao et al。,2013; Lahaye et al。,2013; Stavrou et al。,2015)。在复制过程中,逆转录病毒在细胞质中产生RNA-DNA杂合体和未甲基化的双链前病毒DNA,这是先天免疫传感器的常见靶标(Yan et al。,2010; Gao et al。,2013; Lahaye et ...

Selective Isolation of Retroviruses from Extracellular Vesicles by Intact Virion Immunoprecipitation
Author:
Date:
2018-09-05
[Abstract]  There exists a wide variety of techniques to isolate and purify viral particles from cell culture supernatants. However, these techniques vary greatly in ease of use, purity, yield and impact on viral structural integrity. Most importantly, it is becoming evident that secreted extracellular vesicles (EVs) co-purify with retroviruses using nearly all purification methods due to nearly indistinguishable biophysical characteristics such as size, buoyant density and nucleic acid content. Recently, our group has illustrated a means of isolating intact and highly enriched retroviral virions from EV-containing cell supernatants using an immunoprecipitation approach targeting the viral envelope glycoprotein of the Moloney Murine Leukemia Virus (Renner et al., 2018). This technique, that ... [摘要]  存在多种从细胞培养上清液中分离和纯化病毒颗粒的技术。然而,这些技术在易用性,纯度,产量和对病毒结构完整性的影响方面差异很大。最重要的是,由于几乎无法区分的生物物理特征,例如大小,浮力密度和核酸含量,使用几乎所有纯化方法分泌的细胞外囊泡(EV)与逆转录病毒共同纯化变得明显。最近,我们小组已经阐明了一种利用针对Moloney鼠白血病病毒的病毒包膜糖蛋白的免疫沉淀方法从含有EV的细胞上清液中分离完整和高度富集的逆转录病毒病毒颗粒的方法(Renner et al。, 2018)。这种技术,我们称之为完整的病毒粒子免疫沉淀(IVIP),使我们能够表征这些逆转录病毒表面上表位的可及性,并评估病毒包膜中病毒编码的整合膜蛋白Glycogag(gPr80)的方向。该方案的正确实施使得能够快速,简单且可重复地制备完整且高度纯化的逆转录病毒颗粒,其没有可检测的EV污染物。

【背景】广泛使用的分离逆转录病毒的方法,如人类免疫缺陷病毒(HIV)和小鼠白血病病毒(MLV),包括沉淀,色谱,超滤,超速离心,以及各种其他粒子分离方法(评论在Nestola et al。,2015)。虽然每种技术都有其特定的优点,缺点和局限性,但所有方法的共同关注点是细胞分泌的细胞外囊泡(EV)的共同纯化。

EV构成由所有细胞类型分泌的膜衍生囊泡的异质群体(Yanez-Mo ...

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