{{'Search' | translate}}
 

Potassium phosphate monobasic (KH2PO4)

Company: Merck
Catalog#: P0662
Bio-protocol()
Company-protocol()
Other protocol()

Preparation of Bacterial Outer Membrane Vesicles for Characterisation of Periplasmic Proteins in Their Native Environment
Author:
Date:
2020-12-20
[Abstract]  

Bacterial outer membrane vesicles (OMVs) are naturally formed by budding from the outer membrane of Gram-negative bacteria. OMVs consist of a lipid bilayer identical in composition to the original outer membrane and contain periplasmic content within their lumen. Enriched with specific envelope proteins, OMVs make for an excellent native-like platform to study these proteins in-situ using biophysical methods. Here, we describe in detail the preparation of OMVs from Escherichia coli, which are luminally enriched with periplasmic proteins and uniformly labeled with stable isotopes (2H and 15N), suitable for the subsequent characterisation of proteins at atomic resolution in their native environment by solution-state NMR spectroscopy. The ability to perform structural studies of periplasmic

...
[摘要]  [摘要]细菌外膜囊泡(OMV)是由革兰氏阴性细菌的外膜出芽自然形成的。OMV由组成与原始外膜相同的脂质双层组成,并且在其内腔中含有周质成分。OMV富含特定的包膜蛋白,是使用生物物理方法原位研究这些蛋白的绝佳天然样平台。在这里,我们详细描述了从大肠杆菌制备OMV的方法,该方法在光亮时富含周质蛋白,并用稳定的同位素(2 H和15 N)均匀标记,适用于后续表征溶液状态NMR光谱分析天然环境中蛋白质的原子分辨率。执行周质成分的结构研究的能力,现场清除的方式来REAC兴的这种独特的细胞室的功能和机理细节的深入了解。

[背景]革兰氏阴性菌的周质是一个相当了不起的细胞室。这个空间中,内和外细菌膜之间禁闭,包含在抽蛋白一个ö ř dinarily高浓度超过300毫克毫升-1 (奥利弗,1996) ,并且在不存在的细胞来源,如ATP,功能几乎大力独立从其胞质对应物。到目前为止,有关周质蛋白的结构知识是使用从其天然环境分离的纯化蛋白专门获得的。因此,这种特殊环境可能对蛋白质施加的任何结构和功能影响在纯化过程中都会丢失。由于周质的体积比低,阻碍了使用生物物理方法如细胞内NMR光谱原位研究周质蛋白的努力,周质的体积比仅占细菌总体积的5-1 0%(Brass等,1986)。 )。

...

Use of Optogenetic Amyloid-β to Monitor Protein Aggregation in Drosophila melanogaster, Danio rerio and Caenorhabditis elegans
Author:
Date:
2020-12-05
[Abstract]  

Alzheimer’s Disease (AD) has long been associated with accumulation of extracellular amyloid plaques (Aβ) originating from the Amyloid Precursor Protein. Plaques have, however, been discovered in healthy individuals and not all AD brains show plaques, suggesting that extracellular Aβ aggregates may play a smaller role than anticipated. One limitation to studying Aβ peptide in vivo during disease progression is the inability to induce aggregation in a controlled manner. We developed an optogenetic method to induce Aβ aggregation and tested its biological influence in three model organisms–D. melanogaster, C. elegans and D. rerio. We generated a fluorescently labeled, optogenetic Aβ peptide that oligomerizes rapidly in vivo in the presence of blue light

...
[摘要]  [摘要]Alzheimer'sdisease(AD)长期以来与淀粉样前体蛋白产生的细胞外淀粉样斑块(Aβ)的积聚有关。然而,在健康人身上发现了斑块,并不是所有的AD大脑都有斑块,这表明细胞外Aβ聚集体的作用可能比预期的要小。在疾病进展过程中研究Aβ肽的一个局限性是无法以可控的方式诱导聚集。我们开发了一种诱导Aβ聚集的光遗传学方法,并在三种模式生物中测试了其生物学效应:D.melanogaster、C.elegans和D.rerio。我们产生了一个荧光标记的,光生的

一种β肽,在所有生物体内,在蓝光存在下迅速寡聚。在这里,我们详细介绍了在动物模型中表达该融合蛋白的程序,使用延时光片显微镜研究对神经系统的影响,并进行代谢分析来测量由于细胞内Aβ聚集而引起的变化。这种方法利用光遗传学来研究AD的病理学,实现了目前任何其他方法都无法实现的体内时空控制。

[背景]阿尔茨海默病(AD)是一种衰弱的、与年龄相关的神经退行性疾病(Zhang等人,2011年;De ...

TetR Regulated in vivo Repression Technology to Identify Conditional Gene Silencing in Genetically Engineerable Bacteria Using Vibrio cholerae Murine Infections as Model System
Author:
Date:
2020-10-05
[Abstract]  Investigation of bacterial gene regulation upon environmental changes is still a challenging task. For example, Vibrio cholerae, a pathogen of the human gastrointestinal tract, faces diverse transient conditions in different compartments upon oral ingestion. Genetic reporter systems have been demonstrated to be extremely powerful tools to unravel gene regulation events in complex conditions, but so far focused mainly on gene induction. Herein, we describe the TetR-controlled recombination-based in vivo expression technology TRIVET, which allows detection of gene silencing events. TRIVET resembles a modified variant of the in vivo expression technology (IVET) as well as recombination-based in vivo expression technology (RIVET), which were used to ... [摘要]  [摘要]研究细菌基因对环境变化的调控仍然是一项艰巨的任务。例如,人胃肠道的病原体霍乱弧菌在口服后会在不同的隔室中遇到各种短暂的状况。事实证明,遗传报告系统是揭示复杂条件下基因调控事件的极有力工具,但到目前为止,它主要集中在基因诱导上。在本文中,我们描述了基于TetR控制的重组的体内表达技术TRIVET,该技术可检测基因沉默事件。TRIVET类似于体内表达技术(IVET)以及基于重组的体内变异体 表达技术(RIVET),用于鉴定宿主定殖过程中几种细菌的条件基因诱导。像它的前辈一样,TRIVET是一个基于单细胞的报告系统,可以通过耐药谱的表型变化以时空方式分析细菌基因的阻遏。简而言之,无启动子的tetR (编码转录阻遏物TetR)可通过转座子诱变随机地整合到细菌基因组中,或通过同源重组在目标启动子的下游特异性整合到细菌基因组中。的TetR导致的去阻遏的转录表达的减少的TetR控制解离TNPR,这反过来又导致切除ö F A Ñ抗生素抗性盒(也称为RES-盒)和改变的电阻曲线可观察到的通过划线上氨苄青霉素和卡那霉素板。然后可以将这种改变量化为抗性和非抗性分离株之间的比例。此外,新引入的第二报道基因,promot erless ...

Comments