Simplified Preservation of Equivalent Pathways Spectroscopy

• DOI: 10.1021/jacsau.3c00312
• Publication Date: 2023-10-11T11:29:40Z
• Authors: Evgeny Nimerovsky; Abel Cherian Varkey; Myeongkyu Kim; Stefan Becker; Loren B. Andreas
• Keywords: Magnetization transfer; Magic angle spinning

Inspired by the recently proposed transverse mixing optimal control pulses (TROP) approach for improving signal in multidimensional magic-angle spinning (MAS) NMR experiments, we present simplified preservation of equivalent pathways spectroscopy (SPEPS). It transfers both components magnetization that occur during indirect evolutions, theoretically enabling a √2 improvement sensitivity each such dimension. We compare SPEPS transfer with TROP and cross-polarization (CP) using membrane protein fibril samples at MAS 55 100 kHz. In three-dimensional (3D) (H)CANH spectra, outperformed CP factors on average 1.16 1.69, respectively, protein, but only marginal 1.09 was observed fibril. These differences are discussed, making note longer time used CP, 14 ms, as compared 2.9 3.6 ms TROP, respectively. Using two 3D (H)CANCO experiment resulted an even larger benefit intensity, 1.82 CP. This results multifold savings, particular considering weaker peaks to most from SPEPS.