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Author:
Date:
2016-09-20
[Abstract] Starch biosynthesis in plants involves a network of enzymes of which adenosine-5’-diphosphoglucose (ADP-glucose) pyrophosphorylase (AGPase, E.C. 2.7.7.27), and soluble and granule bound starch synthases (SSS and GBSS, E.C. 2.4.1.21) play central roles. Here, we outline the protocol for extraction and assay of these enzymes in developing grains of wheat (Triticum aestivum L.). The principle of the assays outlined is based on a coupling enzymatic reactions where the product of the initial reaction is used as a substrate for subsequent reactions in order to generate NADPH, which can be measured easily by spectrophotometer. This protocol does not need expensive labelled chemicals and can be carried out using equipment commonly found in a biochemical laboratory. We applied this ...
[摘要] 植物中的淀粉生物合成涉及酶的网络，其中腺苷-5'-二磷酸葡萄糖（ADP-葡萄糖）焦磷酸化酶（AGPase，EC 2.7.7.27）和可溶性和颗粒结合的淀粉合酶（SSS和GBSS，EC 2.4.1.21）中心角色。在这里，我们概述了用于提取和测定这些酶在开发小麦谷粒（ Triticum aestivum L）中的方案。概述的测定法的原理基于偶联酶反应，其中初始反应的产物用作随后反应的底物，以便产生NADPH，其可以通过分光光度计容易地测量。该方案不需要昂贵的标记的化学品，并且可以使用通常在生化实验室中发现的设备进行。我们应用这个协议来研究开花后不同时间点小麦籽粒中AGPase，SSS和GBSS活性的动力学。
[背景] 淀粉是一种碳水化合物聚合物由α-1,4-连接的葡萄糖分子组成的线性葡聚糖聚合物和支链淀粉（由α-1,6-糖苷键支化的α-1,4-连接的葡萄糖分子组成的另一种葡聚糖聚合物）。腺苷-5'-二磷酸葡萄糖（ADP-葡萄糖）焦磷酸化酶（AGPase，E.C.2.7.7.27）催化淀粉合成的第一承诺步骤，将葡萄糖-1-磷酸和ATP转化为ADP-葡萄糖和无机焦磷酸（PPi）。 ADP-葡萄糖随后被可溶性淀粉合成酶（SSS）和颗粒结合的淀粉合酶（GBSS）（EC 2.4.1.21）和淀粉分支酶使用以延长和分支淀粉颗粒的葡聚糖链。 ...
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