Open AccessModest Offset Difference Internuclear Selective Transfer via Homonuclear Dipolar Coupling
Author(s) -
Evgeny Nimerovsky,
Eszter E. Najbauer,
Kumar Tekwani Movellan,
Kai Xue,
Stefan Becker,
Loren B. Andreas
Publication year - 2022
Publication title -
the journal of physical chemistry letters
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.1c03871
Subject(s) - homonuclear molecule , pulse sequence , magic angle spinning , spins , proton , magnetic dipole–dipole interaction , chemistry , nuclear magnetic resonance , dipole , spinning , magic angle , molecular physics , heteronuclear molecule , solid state nuclear magnetic resonance , atomic physics , nuclear magnetic resonance spectroscopy , physics , molecule , condensed matter physics , nuclear physics , organic chemistry , polymer chemistry
Homonuclear dipolar recoupling is routinely used for magic-angle spinning NMR-based structure determination. In fully protonated samples, only short proton-proton distances are accessible to broadband recoupling approaches because of high proton density. Selective methods allow detection of longer distances by directing polarization to a subset of spins. Here we introduce the selective pulse sequence MODIST, which recouples spins that have a modest chemical shift offset difference, and demonstrate it to selectively record correlations between amide protons. The sequence was selected for good retention of total signal, leading to up to twice the intensity for proton-proton correlations compared with other selective methods. The sequence is effective across a range of spinning conditions and magnetic fields, here tested at 55.555 and 100 kHz magic-angle spinning and at proton Larmor frequencies from 600 to 1200 MHz. For influenza A M2 in lipid bilayers, cross-peaks characteristic of a helical conformation are observed.