High-Resolution 2D NMR Spectroscopy of Bicelles To Measure the Membrane Interaction of Ligands

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• 作者：Sergey V. Dvinskikh ; Ulrich H. N. D&uuml ; rr ; Kazutoshi Yamamoto ; Ayyalusamy Ramamoorthy
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：January 31, 2007
• 年：2007
• 卷：129
• 期：4
• 页码：794 - 802
• 全文大小：166K
• 年卷期：v.129,no.4(January 31, 2007)
• ISSN：1520-5126

文摘

Magnetically aligned bicelles are increasingly being used as model membranes in solution- andsolid-state NMR studies of the structure, dynamics, topology, and interaction of membrane-associatedpeptides and proteins. These studies commonly utilize the PISEMA pulse sequence to measure dipolarcoupling and chemical shift, the two key parameters used in subsequent structural analysis. In the presentstudy, we demonstrate that the PISEMA and other rotating-frame pulse sequences are not suitable for themeasurement of long-range heteronuclear dipolar couplings, and that they provide inaccurate values whenmultiple protons are coupled to a ¹³C nucleus. Furthermore, we demonstrate that a laboratory-frameseparated-local-field experiment is capable of overcoming these difficulties in magnetically aligned bicelles.An extension of this approach to accurately measure ¹³C-³¹P and ¹H-³¹P couplings from phospholipids,which are useful to understand the interaction of molecules with the membrane, is also described. In these2D experiments, natural abundance ¹³C was observed from bicelles containing DMPC and DHPC lipidmolecules. As a first application, these solid-state NMR approaches were utilized to probe the membraneinteraction of an antidepressant molecule, desipramine, and its location in the membrane.