High-resolution 2D NMR spectroscopy of bicelles to measure the membrane interaction of ligands
2007 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 129, no 4, 794-802 p.Article in journal (Refereed) Published
Magnetically aligned bicelles are increasingly being used as model membranes in solution- and solid-state NMR studies of the structure, dynamics, topology, and interaction of membrane-associated peptides and proteins. These studies commonly utilize the PISEMA pulse sequence to measure dipolar coupling and chemical shift, the two key parameters used in subsequent structural analysis. In the present study, we demonstrate that the PISEMA and other rotating-frame pulse sequences are not suitable for the measurement of long-range heteronuclear dipolar couplings, and that they provide inaccurate values when multiple protons are coupled to a C-13 nucleus. Furthermore, we demonstrate that a laboratory-frame separated-local-field experiment is capable of overcoming these difficulties in magnetically aligned bicelles. An extension of this approach to accurately measure C-13-P-31 and H-1-P-31 couplings from phospholipids, which are useful to understand the interaction of molecules with the membrane, is also described. In these 2D experiments, natural abundance C-13 was observed from bicelles containing DMPC and DHPC lipid molecules. As a first application, these solid-state NMR approaches were utilized to probe the membrane interaction of an antidepressant molecule, desipramine, and its location in the membrane.
Place, publisher, year, edition, pages
2007. Vol. 129, no 4, 794-802 p.
solid-state nmr, heteronuclear dipolar couplings, magainin antimicrobial peptides, magic-angle, phospholipid-bilayers, protein structure, magnetic-resonance, cross-polarization, 2-dimensional nmr, aligned bicelles
IdentifiersURN: urn:nbn:se:kth:diva-16336DOI: 10.1021/ja065536kISI: 000243683800031ScopusID: 2-s2.0-33846609269OAI: oai:DiVA.org:kth-16336DiVA: diva2:334378
QC 201005252010-08-052010-08-05Bibliographically approved