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Updated: Apr 21, 2026
14:55
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
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Breaking the 13C-13C Polarization Transfer Barrier for High-Dimensional Protein Solid-State NMR with Ultra-Fast MAS
Tatsuya Matsunaga1,2, Tsukito So1,2, Ryo Takahashi1
1School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
ACS Measurement Science Au
|April 20, 2026
Summary
We developed SMART-HCP, an efficient method for solid-state NMR (SSNMR) to improve 13C-13C transfers in protein analysis. This technique significantly speeds up high-dimensional SSNMR experiments, enabling faster structural studies of proteins and other materials.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (SSNMR) Spectroscopy
- Biophysical Chemistry
- Structural Biology
Background:
- High-dimensional SSNMR (HD-SSNMR) is crucial for protein analysis but limited by signal loss during polarization transfers.
- Efficient 13C-13C transfers are particularly challenging in HD-SSNMR, hindering detailed structural insights.
- Ultra-fast magic angle spinning (UFMAS) at >60 kHz advances 1H-detected SSNMR capabilities.
Purpose of the Study:
- To overcome signal loss in 13C-13C transfers for HD-SSNMR.
- To introduce a novel homonuclear cross-polarization (HCP) scheme for enhanced efficiency.
- To accelerate protein structure determination using SSNMR.
Main Methods:
- Development and implementation of the SeMi-selective Adiabatic Recoupling Transfer with HCP (SMART-HCP) scheme.
- Optimization of radio frequency (RF)-offset and amplitude modulations for semiselective HCP.
- Application of SMART-HCP in 1H-detected UFMAS SSNMR experiments at 90 kHz on labeled alanine and GB1 proteins.
Main Results:
- SMART-HCP achieved high 13CO-13Cα transfer efficiencies (76% and 70%) in alanine.
- Compared to DREAM, SMART-HCP enhanced 13CO-13Cα transfers up to ~3-fold (average 1.7-fold) in GB1 proteins.
- SMART-HCP accelerated HD-SSNMR experiments by up to ~9-fold, enabling 3D spectra acquisition in 3.5 hours for trace protein samples.
Conclusions:
- SMART-HCP significantly improves 13C-13C transfers, overcoming a key bottleneck in HD-SSNMR.
- This method accelerates protein SSNMR experiments, facilitating rapid structural analysis.
- SMART-HCP is broadly applicable to 13C SSNMR analysis of various solid organic materials, including polymers and pharmaceuticals.
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