| Determination of Fructokinase Activity from Zobellia galactanivorans
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Author:
Date:
2015-11-05
[Abstract] Mannitol is a polyol that occurs in a wide range of living organisms, where it fulfills different physiological roles. Several pathways have been described for the metabolism of mannitol by bacteria, including the phosphoenolpyruvate-dependent phosphotransferase system (PST) and a M2DH-based catabolic pathway. The latter involves two enzymes, a mannitol-2-dehydrogenase (EC 1.1.1.67) and a fructokinase (EC 2.7.1.4), and has been identified in different bacteria, e.g.,, the marine Bacteroidetes Zobellia galactanivorans (Zg) which had recently gained interest to study the degradation of macroalgal polysaccharides. This protocol describes the biochemical characterization of a recombinant fructokinase (FK) of Zobellia galactanivorans. The ZgFK ...
[摘要] 甘露醇是在多种活生物体中发生的多元醇，其中它实现不同的生理作用。已经描述了用于由细菌代谢甘露醇的几种途径，包括磷酸烯醇丙酮酸依赖性磷酸转移酶系统（PST）和基于M2DH的分解代谢途径。后者涉及两种酶，甘露醇-2-脱氢酶（EC 1.1.1.67）和果糖激酶（EC 2.7.1.4），并且已经在不同的细菌中鉴定，例如海洋拟杆菌Zobellia galactanivorans （ Zg ），其最近获得了研究大分子多糖降解的兴趣。该方案描述了Zobellia 半乳糖厌氧杆菌的重组果糖激酶（FK）的生物化学表征。 < strong> [原理] 果糖激酶（FK）活性通过以下方法确定：果糖激酶（FK）活性通过使用ATP作为辅因子来催化果糖转化成果糖-6-磷酸。酶偶联测定（图1）。通过FK反应（即果糖磷酸化成果糖-6-磷酸（F6P））形成的ADP由将磷酸烯醇丙酮酸（PEP）转化为丙酮酸的丙酮酸激酶（PK）使用。然后，乳酸脱氢酶（LDH）使用NADH作为辅因子将丙酮酸转化为乳酸。通过跟随在340nm处的吸光度的降低来测量FK活性，其对应于NADH转化为NAD + 。
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| Determination of Mannitol-2-dehydrogenase Activity
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Author:
Date:
2015-11-05
[Abstract] Mannitol is a polyol that occurs in a wide range of living organisms, where it fulfills different physiological roles. Several pathways have been described for the metabolism of mannitol by bacteria, including the phosphoenolpyruvate-dependent phosphotransferase system (PST) and a M2DH-based catabolic pathway. The latter involves two enzymes, a mannitol-2-dehydrogenase (EC 1.1.1.67) and a fructokinase (EC 2.7.1.4), and has been identified in different bacteria, e.g., the marine Bacteroidetes Zobellia galactanivorans (Zg) which had recently gained interest to study the degradation of macroalgal polysaccharides. This protocol describes the biochemical characterization of a recombinant mannitol-2-dehydrogenase (M2DH) of Zobellia galactanivorans. The Zg ...
[摘要] 甘露醇是在多种活生物体中发生的多元醇，其中它实现不同的生理作用。已经描述了用于由细菌代谢甘露醇的几种途径，包括磷酸烯醇丙酮酸依赖性磷酸转移酶系统（PST）和基于M2DH的分解代谢途径。后者涉及两种酶，甘露醇-2-脱氢酶（EC 1.1.1.67）和果糖激酶（EC 2.7.1.4），并且已经在不同的细菌中鉴定，例如， 海洋拟杆菌（Zobellia galactanivorans）（ Zg ），最近对研究大分子多糖降解有兴趣。该方案描述了半乳聚糖微生物的重组甘露醇-2-脱氢酶（M2DH）的生物化学表征。使用NAD +辅助作为辅因子，M2DH酶催化甘露醇向果糖的可逆转化。 在两个方向上测定M2DH活性，即果糖还原和甘露醇氧化。
可逆反应：
D-甘露醇+ NAD + ↔D-果糖+ NADH + H +
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| Optical Clearing Using SeeDB
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Author:
Date:
2014-02-05
[Abstract] We describe a water-based optical clearing agent, SeeDB (See Deep Brain), which clears fixed brain samples in a few days without quenching many types of fluorescent dyes, including fluorescent proteins and lipophilic neuronal tracers. SeeDB is a saturated solution of fructose (80.2% w/w) in water with 0.5% α-thioglycerol. In standard SeeDB optical clearing procedure, we treat paraformaldehyde-fixed embryo and brain samples with increasing concentrations of aqueous fructose solutions, and finally equilibrate them in SeeDB. The entire procedure takes approximately three days. Unlike previous methods, this method maintains a constant sample volume during the clearing procedure, an important factor to keep cellular morphology intact. After optical clearing, we can reach > 1,000 μm under ...
[摘要] 我们描述了一种水基光学清除剂，SeeDB（参见深脑），其在几天内清除固定的脑样品，而不淬灭许多类型的荧光染料，包括荧光蛋白和亲脂性神经元示踪剂。 SeeDB是果糖（80.2％w/w）在含有0.5％α-硫代甘油的水中的饱和溶液。在标准的SeeDB光学清除程序中，我们用增加浓度的果糖水溶液处理多聚甲醛固定的胚胎和脑样品，并且最后在SeeDB中平衡它们。整个过程大约需要三天。与以前的方法不同，该方法在清除过程中保持恒定的样品体积，这是保持细胞形态完整的重要因素。光学清除后，我们可以达到>在共聚焦显微镜下为1,000μm。当与双光子显微镜结合时，SeeDB允许我们以毫米级别水平成像固定的小鼠大脑。这种方法有助于全面和定量分析理解神经元电路，在成人和发展中国家的小鼠大脑。还提供了SeeDB变体（参见DB37）和优化的程序（见DBp和SeeDB37ht协议）以满足特定要求。
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