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KCl

氯化钾

Company: Sigma-Aldrich
Catalog#: P9541
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SMART (Single Molecule Analysis of Resection Tracks) Technique for Assessing DNA end-Resection in Response to DNA Damage
Author:
Date:
2020-08-05
[Abstract]  DNA double strand breaks (DSBs) are among the most toxic lesions affecting genome integrity. DSBs are mainly repaired through non-homologous end joining (NHEJ) and homologous recombination (HR). A crucial step of the HR process is the generation, through DNA end-resection, of a long 3′ single-strand DNA stretch, necessary to prime DNA synthesis using a homologous region as a template, following DNA strand invasion. DNA end resection inhibits NHEJ and triggers homology-directed DSB repair, ultimately guaranteeing a faithful DNA repair. Established methods to evaluate the DNA end-resection process are the immunofluorescence analysis of the phospho-S4/8 RPA32 protein foci, a marker of DNA end-resection, or of the phospho-S4/8 RPA32 protein levels by Western blot. Recently, the Single ... [摘要]  [摘要] DNA双链断裂(dsb)是影响基因组完整性的最具毒性的损伤之一。dsb主要通过非同源末端连接(NHEJ)和同源重组(HR)进行修复。HR过程的一个关键步骤是通过DNA末端切除,产生一个长的3′单链DNA链,这是在DNA链入侵后,以同源区域为模板进行DNA合成所必需的。DNA末端切除抑制NHEJ并触发同源定向的DSB修复,最终保证DNA的可靠修复。已建立的评价DNA末端切除过程的方法是免疫荧光法分析磷酸化S4/8rpa32蛋白病灶(DNA末端切除的标志物)或磷酸化S4/8rpa32蛋白水平。近年来,切除轨迹单分子分析(SMART)被认为是一种可靠的方法,可以通过免疫荧光法观察S期特异性DNA损伤剂(如喜树碱)处理细胞后产生的长3′单链DNA尾。然后,通过图像分析软件(如Photoshop)测量DNA束长度,评价DNA末端切除机的处理能力。DNA纤维的制备是在非变性条件下进行的,因此免疫荧光只检测DSB处理产生的特定的3′单链DNA尾。

[背景] ...

Purification of Soluble Recombinant Human Tau Protein from Bacteria Using Double-tag Affinity Purification
Author:
Date:
2018-11-20
[Abstract]  Dysfunction of the microtubule-associated protein Tau (encoded by the MAPT gene) has been implicated in more than twenty neurodegenerative diseases, including Alzheimer’s. As such, the physiological and disease-relevant functions of Tau have garnered great interest in the research community. One barrier hampering investigations into the functions of Tau and the generation of pharmacological agents targeting Tau has been the difficulty of obtaining soluble Tau protein in purified form. Here, we describe a protocol that uses dual affinity tag purification to selectively purify soluble recombinant Tau protein from bacteria that is functionally active for downstream applications including immunization, microtubule binding assays, and protein-protein interaction studies. [摘要]  微管相关蛋白Tau(由 MAPT 基因编码)的功能障碍已经涉及20多种神经退行性疾病,包括阿尔茨海默病。 因此,Tau的生理和疾病相关功能引起了研究界的极大兴趣。 妨碍对Tau功能的研究和产生靶向Tau的药理学试剂的一个障碍是难以获得纯化形式的可溶性Tau蛋白。 在这里,我们描述了一种方案,该方案使用双亲和标签纯化从细菌中选择性纯化可溶性重组Tau蛋白,所述细菌对于下游应用具有功能活性,包括免疫,微管结合测定和蛋白质 - 蛋白质相互作用研究。
【背景】Tau传统上被定义为微管结合蛋白;然而,在人类疾病中,Tau可以与轴突微管分离并错误定位到其他神经元区室,包括体细胞,树突和突触,其中与非微管蛋白和结构的相互作用驱动神经元功能障碍(Iqbal et al。 ,2016; Wang和Mandelkow,2016; Zhou et al。,2017; McInnes et al。,2018)。尽管神经原纤维缠结形式的Tau聚集体通常存在于死后患病的脑组织中,但研究表明,可溶性Tau,而不是聚集的Tau,是神经元功能障碍的主要原因(Crimins et al。,2012 ; Polydoro et al。,2014; Koss et al。,2016)。因此,研究Tau在疾病中的可溶性功能,例如鉴定蛋白质 - ...

HIVGKO: A Tool to Assess HIV-1 Latency Reversal Agents in Human Primary CD4+ T Cells
Author:
Date:
2018-10-20
[Abstract]  While able to suppress HIV replication in HIV infected individuals, combination antiretroviral therapy (ART) fails to eliminate viral latent reservoir, which consists in integrated transcriptional silenced HIV provirus. So far, identification of latently-infected cells has relied on activating cells to induce expression of HIV proteins which can then be detected. Unfortunately, this activation significantly changed the cell phenotype. We developed a novel HIV reporter, named HIVGKO, that allows the purification of latently-infected cells in absence of reactivation. Indeed, latent cells can be identified by expression of the EF1a-driven mKO2 and lack of expression of the LTR-driven csGFP. This protocol can be used to study the effectiveness of LRAs (Latency Reversal Agents) in ... [摘要]  虽然能够抑制HIV感染个体中的HIV复制,但联合抗逆转录病毒疗法(ART)无法消除病毒潜伏性储库,其包含整合的转录沉默的HIV原病毒。 到目前为止,潜伏感染细胞的鉴定依赖于激活细胞以诱导HIV蛋白的表达,然后可以检测到这些蛋白的表达。 不幸的是,这种激活显着改变了细胞表型。 我们开发了一种名为HIV GKO 的新型HIV报告基因,可以在没有再激活的情况下纯化潜伏感染的细胞。 实际上,可以通过EF1a驱动的mKO2的表达和LTR驱动的csGFP的缺乏表达来鉴定潜伏细胞。 该方案可用于研究LCA(潜伏期逆转剂)在原代细胞中重新激活潜伏HIV的有效性。

【背景】新版双标记病毒(HIV GKO )含有5'LTR中HIV-1启动子控制下的密码子转换eGFP(csGFP)和一种独特的无关荧光蛋白 mKO2在细胞延伸因子αα启动子(EF1α)的控制下。 当使用与遗传相关的荧光蛋白时,由于重组问题,在这些报道分子中使用不相关的荧光蛋白是很重要的。 因此,生产性感染的细胞主要是csGFP + mKO2 + (有些可能只是GFP + ),而潜伏感染的细胞是csGFP - mKO2 + 。 流式细胞仪如分拣机AriaII允许纯化纯感染人群(生产性,潜伏性和/或未感染),而分析仪LSRII允许评估HIV GKO LTR的转录激活。 感染后的时间很短。

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