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Author:
Date:
2016-08-20
[Abstract] Nicotinamide adenine dinucleotide is a coenzyme present in all kingdoms of life and exists in two forms: oxidized (NAD+) and reduced (NADH). NAD(H) is involved in a multitude of essential metabolic redox reactions, providing oxidizing or reducing equivalents. The ratio of free intracellular NAD+/NADH is fundamentally important in the maintenance of cellular redox homeostasis (Ying, 2008). Various chromogenic cycling assays have been used to determine the ratio of NAD+/NADH in both bacterial and mammalian cells for more than forty years (Bernofsky and Swan, 1973; Nisselbaum and Green, 1969).
Here, we describe in detail an assay to determine the ratio of free intracellular NAD+ to NADH in Streptococcus mutans. This cycling ...
[摘要] 烟酰胺腺嘌呤二核苷酸是存在于生命的所有王国中的辅酶，并且以两种形式存在：氧化（NAD +）和还原（NADH）。 NAD（H）参与多种必需的代谢氧化还原反应，提供氧化或还原等价物。游离细胞内NAD + /NADH的比率在维持细胞氧化还原稳态中是根本重要的（Ying，2008）。已经使用各种显色循环测定来测定细菌和哺乳动物细胞中NAD +/NAD +/NADH的比率超过四十年（Bernofsky和Swan，1973; Nisselbaum和Green，1969）。 /> 在这里，我们详细描述了测定变异链球菌中游离细胞内NAD + 与NADH的比率的测定法。该循环测定是Bernofsky和Swan（Bernofsky和Swan，1973）首先描述的方案的修改版本，使用Frezza等人描述的提取缓冲液。 （2011），随后是由Gibbon和Larher描述的减少的MTT降水（Gibon和Larher，1997）。如图1所示，使用乙醇脱氢酶来驱动一系列氧化还原反应，利用来自样品提取物的外源添加的乙醇和NAD +作为初始底物，吩嗪乙硫酸盐（PES）作为电子载体，以及噻唑基蓝色四唑溴化物（MTT）作为末端电子受体。使用6M ...
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Author:
Date:
2015-03-05
[Abstract] Recently, membrane vesicle (MV) production was described in Gram-positive bacteria, which harbor a variety of components such as toxins, antibiotic resistance proteins, proteases, DNA, and immune modulators. Free lipids have the ability to form micelles, thus it is important to rule out spontaneous association of lipids into vesicle-like structures and rather, that MVs are produced naturally by a metabolically active cell. Here, we describe a protocol utilizing the polysaccharide, glucuronoxylomannan (GXM) from Cryptococcus neoformans (C. neoformans) as a marker to differentiate naturally produced MVs from vesicles that form spontaneously in the Gram-positive model organism, Bacillus subtilis (B. subtilis). MVs are purified from bacterial cultures grown ...
[摘要] 最近，在革兰氏阳性细菌中描述了膜囊泡（MV）产生，其含有多种组分，例如毒素，抗生素抗性蛋白，蛋白酶，DNA和免疫调节剂。游离脂质具有形成胶束的能力，因此排除脂质自发缔合成囊泡样结构是重要的，并且更确切地说，MV由代谢活性细胞天然产生。在这里，我们描述了利用来自新隐孢子虫的多糖葡萄糖醛酸甘露聚糖（GXM）（ C。新型隐球菌）作为标记物来区分天然产生的MV与自发形成的囊泡革兰氏阳性模式生物，枯草芽孢杆菌（<枯草芽孢杆菌）。从在GXM存在下生长的细菌培养物中纯化MV;由细胞天然产生的MV在管腔中不含有GXM，而在培养基中形成的囊泡结构可包封GXM，并且这可通过免疫金属透射电子显微镜可视化。
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