14N Polarization Inversion Spin Exchange at Magic Angle (PISEMA)

Chunqi Qian; Riqiang Fu; Peter Gor'kov; William W Brey; Timothy A Cross; Zhehong Gan

doi:10.1016/j.jmr.2008.10.014

14N Polarization Inversion Spin Exchange at Magic Angle (PISEMA)

J Magn Reson. 2009 Jan;196(1):96-9. doi: 10.1016/j.jmr.2008.10.014. Epub 2008 Oct 17.

Authors

Chunqi Qian¹, Riqiang Fu, Peter Gor'kov, William W Brey, Timothy A Cross, Zhehong Gan

Affiliation

¹ Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA.

PMID: 18986816
DOI: 10.1016/j.jmr.2008.10.014

Abstract

Polarization Inversion Spin Exchange at Magic Angle (PISEMA) is a powerful experiment for determining peptide orientation in uniformly aligned samples such as planar membranes. In this paper, we present (14)N-PISEMA experiment which correlates (14)N quadrupolar coupling and (14)N-(1)H dipolar coupling. (14)N-PISEMA enables the use of (14)N quadrupolar coupling tensor as an ultra sensitive probe for peptide orientation and can be carried out without the need of isotope enrichment. The experiment is based on selective spin-exchange between a proton and a single-quantum transition of (14)N spins. The spin-exchange dynamics is described and the experiment is demonstrated with a natural abundant N-acetyl valine crystal sample.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Algorithms*
Computer Simulation
Magnetic Resonance Spectroscopy / methods*
Membrane Proteins / chemistry*
Membrane Proteins / ultrastructure*
Models, Chemical*
Models, Molecular
Nitrogen / analysis
Nitrogen / chemistry*
Protein Conformation

Substances

Membrane Proteins
Nitrogen