title: Mismatched Hartmann-Hahn conditions cause proton-mediated intermolecular magnetization transfer between dilute low-spin nuclei in NMR of static solids.
abstract: Mismatched Hartmann-Hahn conditions between the protons and dilute spins (such as 15N) are found to cause intermolecular magnetization transfer between the low-gamma nuclei over long distances. This transfer is purely proton mediated and occurs even in the absence of direct 15N-15N couplings. This has been demonstrated experimentally using a static single crystal of n-acetyl Leucine with intermolecular distances between the 15N nuclei exceeding 6.5 A. A quantum-mechanical explanation of this phenomenon is given based on the average-Hamiltonian theory which was confirmed by detailed numerical many-spin simulations. The theory and experiment presented in the present paper may help in the development of solid-state NMR methods for studying interhelical contacts in membrane proteins, as well as for their spectral assignment.
authors.affiliation: Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, USA. alex_nevzorov@ncsu.edu
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Nevzorov
mesh_terms: D000107:Acetylation; D003198:Computer Simulation; D007930:Leucine / Q000031:analogs & derivatives; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008565:Membrane Proteins / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D009587:Nitrogen Isotopes / Q000737:chemistry; D011522:Protons; D011789:Quantum Theory; D013113:Spin Labels
chemical_list: D008565:Membrane Proteins; D009587:Nitrogen Isotopes; D011522:Protons; D013113:Spin Labels; D007930:Leucine