Double-acquisition: Utilization of discarded coherences in a 2D separation experiment using the States method

Orphan spin operators enable the acquisition of multiple 2D and 3D magic angle spinning solid-state NMR spectra

“…1 Sensitivity and resolution of the resonances (typically 1 H, 13 C, and 15 N) in multidimensional NMR spectra are fundamental requirements for protein structural analysis. In spite of the most recent progress, multidimensional ssNMR experiments still require many days or weeks of spectrometer time.…”

“…While in liquid-state NMR there are several pulse sequences designed to detect discarded coherences via dual receivers or phase cycling schemes, 4 in ssNMR there are only a few examples that utilize orphan (i.e., neglected) spin operators to boost sensitivity. [5][6][7][8][9][10][11][12][13] In general, classical ssNMR pulse sequences eliminate orphan spin operators of magnetization either using z-filters or phase cycling schemes that suppress the spectral artifacts arising from undesired coherence transfer pathways.…”

“…vegli001@umn.edu ning (DUMAS) approach, 9, 10 which uses simultaneous crosspolarization (SIM-CP) between 1 H, 13 C, and 15 N and enable the simultaneous acquisition of two 2D or 3D experiments.…”

“…In this article, we present a new method, MEIOSIS (Multiple ExperIments via Orphan SpIn operatorS) that enables one to simultaneously acquire multiple multidimensional NMR spectra of uniformly 13 C, 15 N-labeled proteins. This new method utilizes two elements that were instrumental for the DUMAS approach: SIM-CP and long-living 15 N polarization.…”

“…However, MEIOSIS also exploits the residual magnetization of NCA or NCO from specific-CP to generate phase-encoded coherence pathways that are decoded into four independent spectra using Hadamard transformations. To demonstrate the power of this method, we simultaneously acquired four 2D experiments (DARR, 15 N(CA)CX, NCO, and CA(N)CO 16 ) and three 3D experiments (NCACX, NCOCX, and CA(N)COCX 17,18 ) on a U- 13 C, 15 N-labeled microcrystalline ubiquitin. Hadamard decoding the coherences into multiple independent spin operators is a general concept in NMR and can be used to redesign many pulse sequences.…”