| Extraction and Quantification of Tryptophan and Kynurenine from Cultured Cells and Media Using a High Performance Liquid Chromatography (HPLC) System Equipped with an Ultra-sensitive Diode Array Detector
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Author:
Date:
2016-04-05
[Abstract] Evidence of the involvement of tryptophan and its metabolite, kynurenine, in various biological processes including cancer is constantly expanding. Analysis of cell extracts and culture media can allow for quick snapshots of the metabolic fluctuations occurring in vitro. Here, we describe a method for metabolite extraction from mammalian cells and analysis of extracted metabolites and cell culture media by HPLC with detection using an ultra-sensitive diode array detector.
[摘要] 色氨酸及其代谢物，犬尿氨酸参与包括癌症在内的各种生物过程的证据不断扩大。 细胞提取物和培养基的分析可以允许在体外发生的代谢波动的快速快照。 在这里，我们描述了一种从哺乳动物细胞代谢物提取的方法，提取代谢物和细胞培养基通过HPLC检测使用超敏二极管阵列检测器分析。
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| RAB21 Activity Assay Using GST-fused APPL1
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Author:
Date:
2016-02-20
[Abstract] The Rab family of small GTPases are essential regulators of membrane trafficking events. As with other small GTPase families, Rab GTPases cycle between an inactive GDP- bound state and an active GTP-bound state. Guanine nucleotide exchange factors (GEFs) promote Rab activation with the exchange of bound GDP for GTP, while GTPase-activating proteins (GAPs) regulate Rab inactivation with GTP hydrolysis. Numerous methods have been established to monitor the activation status of Rab GTPases. Of those, FRET-based methods are used to identify when and where a Rab GTPase is activated in cells. Unfortunately, the generation of such probes is complex, and only a limited number of Rabs have been probed this way. Biochemical purification of activated Rabs from cell or tissue extracts is easily ...
[摘要] 小GTP酶的Rab家族是膜运输事件的必要调节剂。与其他小GTP酶家族一样，Rab GTP酶在不活动的GDP结合状态和活性GTP结合状态之间循环。鸟嘌呤核苷酸交换因子（GEF）促进Rab激活与交换绑定GDP GTP，而GTPase激活蛋白（GAP）调节Rab失活与GTP水解。已经建立了许多方法来监测Rab GTPases的活化状态。其中，基于FRET的方法用于鉴定细胞中Rab GTPase在何时和何地被激活。不幸的是，这种探针的产生是复杂的，并且只有有限数量的Rab已经以这种方式探测。来自细胞或组织提取物的活化的Rabs的生物化学纯化通过使用已知的Rab效应结构域以下拉特定的GTP结合的Rab形式是容易实现的。虽然这种方法不是理想的详细的亚细胞定位，它可以提供Rab活动的时间分辨率。越来越多的特异性效应物的鉴定现在允许在特定条件下测试许多Rab GTP酶的活化水平。在这里，我们描述了一种亲和纯化方法使用GST融合APPL1（一种已知的RAB21效应）来测试哺乳动物细胞中的RAB21激活。该方法成功地用于测定RAB21激活状态下营养丰富与饥饿条件下的变化，并测试在此过程中MTMR13 RAB21 GEF的需求。
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| Assessment of Brown Adipocyte Thermogenic Function by High-throughput Respirometry
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Author:
Date:
2015-11-05
[Abstract] Brown adipose tissue (BAT) has the unique ability to dramatically increase mitochondrial uncoupled fuel oxidation for thermogenesis in response to adrenergic stimulation. A key parameter in assessing brown adipocyte thermogenic capacity is mitochondrial uncoupling as determined by respiration. Measuring mitochondrial oxygen consumption rate (OCR) therefore provides valuable information to study the regulation and dysregulation of fuel metabolism and energy expenditure. Adding measurements of mitochondrial membrane potential allows for more in-depth interpretation of the respirometry data. Here we provide protocols for measuring respiration in adherent intact and plasma membrane permeabilized brown adipocytes using the Seahorse XF Analyzer. In the protocol Part I, a combination of ...
[摘要] 棕色脂肪组织（BAT）具有显着增加线粒体解偶联燃料氧化以响应肾上腺素刺激的热生成的独特能力。评估棕色脂肪细胞产热能力的关键参数是通过呼吸确定的线粒体解偶联。因此，测量线粒体氧消耗率（OCR）为研究燃料代谢和能量消耗的调节和失调提供了有价值的信息。添加线粒体膜电位的测量允许更加深入地解释呼吸数据。在这里我们提供使用Seahorse XF分析仪测量贴壁完整和质膜透性棕色脂肪细胞呼吸的协议。在方案部分I中，去甲肾上腺素和游离脂肪酸的组合用于诱导解偶联呼吸。然后使用ATP合酶抑制剂寡霉素，化学去偶联剂FCCP和复合物III抑制剂抗霉素A分别测量偶联的，最大的和非线粒体的氧消耗。在方案第II部分中，质膜用重组perfringolysin O透化，胆固醇依赖性细胞溶解素寡聚化成在质膜中专门的孔。这允许代谢物可用性的实验性控制，而不从天然细胞环境中分离线粒体。
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