| Measurement of ATP Hydrolytic Activity of Plasma Membrane H+-ATPase from Arabidopsis thaliana Leaves
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Author:
Date:
2016-12-05
[Abstract] Plant plasma membrane H+-ATPase, which is a P-type ATPase, couples ATP hydrolysis to H+ extrusion and thereby generates an electrochemical gradient across the plasma membrane. The proton gradient is necessary for secondary transport, cell elongation, and membrane potential maintenance. Here we describe a protocol for measurement of the ATP hydrolytic activity of the plasma membrane H+-ATPase from Arabidopsis thaliana leaves.
[摘要] 作为P型ATP酶的植物质膜H sup + -ATPase将ATP水解耦合到H + +/- 挤出，从而在质膜上产生电化学梯度。质子梯度对于二次转运，细胞伸长和膜电位维持是必需的。这里我们描述用于测量来自拟南芥叶片的质膜H + -ATPase的ATP水解活性的方案。
关键词： strong> 拟南芥，ATP水解活性，原钒酸盐，P-型ATP酶，血浆膜H + -ATPase
质膜H + -ATPase活性的测定对于阐明其功能和调节机制是重要的。然而，有时难以确定质膜H sup + -ATP酶的ATP水解活性，因为植物细胞含有许多ATP水解酶。该协议是基于Uemura和Yoshida（1986）和Kinoshita等人的出版物开发的。 （1995）。我们使用KNO 3作为V型ATP酶的抑制剂，钼酸铵作为酸性磷酸酶的抑制剂，寡霉素作为F型ATP酶的抑制剂，NaF作为磷酸酶的抑制剂（Shimazaki和Kondo ，1987; Kinoshita等人，1995）。原钒酸盐抑制P型ATP酶，并且因此可以通过评估来自ATP水解的钒酸盐敏感性P 1释放来用于测量质膜H sup + -ATP酶的活性。释放的P 1与钼酸盐反应形成蓝色络合物，然后可以通过测量在750nm的吸收来量化。
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| Purification of a Protein Exhibiting Isoleucine 2-epimerase Activity from Lactobacillus otakiensis JCM 15040
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Author:
Date:
2015-10-20
[Abstract] Prominent accumulation of D-leucine, D-allo-isoleucine and D-valine was observed in the culture medium of the heterofermentative bacterial species, Lactobacillus otakiensis (L. otakiensis) JCM 15040. The racemase enzyme that resulted in this accumulation, isoleucine 2-epimerase, was purified from the bacterial cells. This is the first reported observation of such production of D-branched chain amino acids in lactic acid bacteria, and the first example of a racemase with isoleucine 2-epimerase activity in any organisms. In the described protocol, we introduce methods for purification of this protein from L. otakiensis JCM 15040. Because no specific ligand that has high affinity for this enzyme has been identified, the purification was performed using ...
[摘要] 在异质发酵细菌物种，例如otakiensis的乳酸杆菌（Lactobacillus otakiensis）的培养基中观察到D-亮氨酸，D-异亮氨酸 - 异亮氨酸和D-缬氨酸的显着积累。 otakiensis）JCM 15040.从细菌细胞中纯化导致这种积累的消旋酶，异亮氨酸2-差向异构酶。这是首次报道的在乳酸菌中这种D-支链氨基酸的产生的观察结果，以及在任何生物体中具有异亮氨酸2-差向异构酶活性的消旋酶的第一个实例。在所述的方案中，我们介绍从L中纯化该蛋白质的方法。因为没有鉴定到对该酶具有高亲和力的特异性配体，所以使用硫酸铵级分，四种类型的柱层析和制备型Native-PAGE，不使用亲和柱层析进行纯化。我们希望协议将提供有用的信息用于纯化不能容易地使用亲和柱层析纯化的酶。
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