Towards complete suppression of diagonal peaks in solid-state MAS NMR homonuclear chemical shift correlation spectra

• Published in: Journal of magnetic resonance (1997) Vol. 378; p. 107926
• Main Authors: Zhang, Shengyu, Li, Yuchen, Ye, Yansheng, Tian, Fang, Peng, Xinhua, Fu, Riqiang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2025
• Subjects: 13C–13C chemical shift correlation spectra; Data processing; Diagonal peak suppression; Solid-state MAS NMR; Spin echo; 13C–13C chemical shift correlation spectra; Solid-state MAS NMR; Data processing; Spin echo; Diagonal peak suppression; C–C chemical shift correlation spectra
• ISSN: 1090-7807; 1096-0856; 1096-0856
• DOI: 10.1016/j.jmr.2025.107926

The feasibility of applying the spin-echo based diagonal peak suppression method in solid-state MAS NMR homonuclear chemical shift correlation experiments is demonstrated. A complete phase cycling is designed to generate sine- and cosine-modulations of the chemical shift difference between the spin-diffused signals, enabling the quadrature detection in the indirect dimension. Meanwhile, all signals not involved in polarization transfer are refocused at the center of the indirect dimension. A data processing algorithm is developed to extract and suppress these spin-echo refocused signals without affecting nearby spin-diffused cross peaks. The processed spectrum is then converted into a conventional two-dimensional homonuclear chemical shift correlation spectrum, free of diagonal peaks. The effectiveness of this method is illustrated using a uniformly 13C-labeled Fmoc-leucine sample and a sample of human Atg8 homolog LC3B, directly conjugated to the amino headgroup of phosphatidylethanolamine (PE) lipids in liposomes. [Display omitted] •Spin-echo based diagonal peak suppression is presented in solid-state MAS NMR.•Quadrature detection is achieved in the indirect dimension.•A data processing algorithm is proposed to remove the spin-echo refocused signals.•Efficient diagonal peak suppression is illustrated using a reference and protein samples.