Study of ion translocation by respiratory complex I. A new insight using 23Na NMR spectroscopy
Study of ion translocation by respiratory complex I. A new insight using 23Na NMR spectroscopy
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DOI：
10.1016/j.bbabio.2012.03.009
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发表时间：
2012-10-01
影响因子：
4.3
通讯作者：
Pereira, Manuela M.
中科院分区：
文献类型：
--
作者：
Batista, Ana P.;Marreiros, Bruno C.;Pereira, Manuela M.
复合体I的研究近年来又有了新的发展，特别是在细菌和线粒体复合体的晶体结构解析之后。现在最关注的是能量耦合机制的研究。质子已被确定为耦合离子，尽管在某些细菌复合物的情况下，I Na+已被提出具有该作用。我们已经解决了一些配合物I与Na+的关系，并开发了一种创新的方法，使用Na-23 NMR光谱。这使得调查的Na+运输的优势，直接监测Na+浓度的变化。这里讨论了有关使用Na-23 NMR光谱准确测量细菌膜囊泡中钠转运的方法学方面。通过两种不同的方法测定外囊泡Na+浓度：1）通过共振频率峰的积分和2）使用共振频率偏移依赖于Na+浓度的校准曲线。虽然校准曲线是一种合适的方法来确定Na+浓度变化的快速交换条件下，它被证明是不适用于细菌膜囊泡系统。在这种情况下，共振频率峰的积分是用于定量外部囊泡Na+浓度的最合适的分析。本文是题为：第17届欧洲生物能学会议（EBEC 2012）的特刊的一部分。(C)2012爱思唯尔有限公司版权所有。
The research on complex I has gained recently a new enthusiasm, especially after the resolution of the crystallographic structures of bacterial and mitochondrial complexes. Most attention is now dedicated to the investigation of the energy coupling mechanism(s). The proton has been identified as the coupling ion, although in the case of some bacterial complexes I Na+ has been proposed to have that role. We have addressed the relation of some complexes I with Na+ and developed an innovative methodology using Na-23 NMR spectroscopy. This allowed the investigation of Na+ transport taking the advantage of directly monitoring changes in Na+ concentration. Methodological aspects concerning the use of Na-23 NMR spectroscopy to measure accurately sodium transport in bacterial membrane vesicles are discussed here. Externalvesicle Na+ concentrations were determined by two different methods: 1) by integration of the resonance frequency peak and 2) using calibration curves of resonance frequency shift dependence on Na+ concentration. Although the calibration curves are a suitable way to determine Na+ concentration changes under conditions of fast exchange, it was shown not to be applicable to the bacterial membrane vesicle systems. In this case, the integration of the resonance frequency peak is the most appropriate analysis for the quantification of external-vesicle Na+ concentration. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). (C) 2012 Elsevier B.V. All rights reserved.