Detection of Protein Interactions in the Cytoplasm and Periplasm of Escherichia coli by Förster Resonance Energy Transfer
|
Author:
Date:
2018-01-20
[Abstract] This protocol was developed to qualitatively and quantitatively detect protein-protein interactions in Escherichia coli by Förster Resonance Energy Transfer (FRET). The described assay allows for the previously impossible in vivo screening of periplasmic protein-protein interactions. In FRET, excitation of a donor fluorescent molecule results in the transfer of energy to an acceptor fluorescent molecule, which will then emit light if the distance between them is within the 1-10 nm range. Fluorescent proteins can be genetically encoded as fusions to proteins of interest and ...
[摘要] 该协议的开发是通过Förster共振能量转移(FRET)定性和定量检测大肠杆菌中的蛋白质 - 蛋白质相互作用。所描述的测定允许以前不可能的周质蛋白质 - 蛋白质相互作用的体内筛选。在FRET中,供体荧光分子的激发导致能量转移到受体荧光分子,如果它们之间的距离在1-10nm范围内,则受体荧光分子将发光。荧光蛋白质可以被遗传编码为与感兴趣的蛋白质的融合物并且在细胞中表达,因此FRET蛋白质 - 蛋白质相互作用实验可以在体内进行。供体和受体荧光蛋白融合体被构建用于被怀疑相互作用的细菌蛋白质。这些融合蛋白在细菌细胞中共表达,随后激发供体和受体通道测量荧光发射光谱。供体的发射光谱与受体的激发光谱之间的部分重叠是FRET的先决条件。即使在没有FRET的情况下,供体激发也可以使受体以已知百分比交叉激发。通过测量背景,仅供体和仅受体样品的参考光谱,可以计算预期的发射光谱。在预期光谱之上的受体的致敏发射可以归因于FRET,并且可以通过光谱解混来量化。
【背景】确定如何和哪些蛋白质相互作用维持生命是分子生物学研究的核心。存在许多体外方法,但可能导致误报,因为相互作用是从其生物学背景中取出的。 ...
|
|
Synchronize Human Embryonic Stem Cells at Different Cell Cycle Stage
|
Author:
Date:
2012-06-05
[Abstract] Pluripotency and the capability for self-renewal are essential characteristics of human embryonic stem cells (hESCs), which hold great potential as a cellular source for tissue replacement. Short cell cycle (15-16 h) compared to somatic cells is another property of hESCs. Efficient synchronization of hESCs at different cell cycle stages is important to elucidate the mechanistic link between cell cycle regulation and cell fate decision. This protocol describes how to establish synchronization of hESCs at different cell cycle stages.
[摘要] 人胚胎干细胞(hESCs)的基本特征是多潜能性和有自我更新的能力,有潜力作为组织替换的细胞供源。和体细胞相比,hESCs有很短的细胞周期这是它的另一个主要体征。不同hESCs细胞周期的高效的同步化对于阐明细胞周期调控和细胞分化之间的关系机制十分的重要。
|
|