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Updated: May 12, 2026

NMR-Based Fragment Screening in a Minimum Sample but Maximum Automation Mode
Published on: June 4, 2021
Ab initio NMR chemical-shift calculations based on the combined fragmentation method
Hwee-Jia Tan1, Ryan P A Bettens
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543. chmbrpa@nus.edu.sg
The combined fragmentation method (CFM) accurately computes NMR chemical shifts for small proteins. Including nonbonded interactions significantly improves accuracy, reducing root mean square errors for key nuclei.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Biomolecular Modeling
Background:
- Nuclear Magnetic Resonance (NMR) chemical shift is a fundamental molecular property.
- Accurate computation of NMR chemical shifts from first principles is crucial for molecular structure elucidation.
- Existing computational methods may face challenges in accuracy and efficiency for larger systems like proteins.
Purpose of the Study:
- To evaluate the accuracy of the combined fragmentation method (CFM) for computing NMR chemical shifts in small proteins.
- To assess the impact of including nonbonded interactions on the accuracy of CFM calculations.
- To provide a computationally efficient yet accurate approach for predicting NMR chemical shifts.
Main Methods:
- Implementation and application of the combined fragmentation method (CFM) for quantum chemical calculations.
- Calculation of NMR chemical shifts for (1)H, (13)C, (15)N, (17)O, and (33)S nuclei in small proteins.
- Comparison of CFM results with and without the inclusion of nonbonded interactions against full calculations.
Main Results:
- Without nonbonded interactions, CFM achieved root mean square errors (RMSEs) of 0.340 ppm for (1)H, 0.649 ppm for (13)C, 3.052 ppm for (15)N, 6.928 ppm for (17)O, and 0.122 ppm for (33)S.
- With nonbonded interactions, RMSEs were significantly reduced to 0.038 ppm for (1)H, 0.253 ppm for (13)C, 0.681 ppm for (15)N, 3.480 ppm for (17)O, and 0.052 ppm for (33)S.
- The inclusion of nonbonded interactions dramatically improved the accuracy of CFM predictions for all studied nuclei.
Conclusions:
- The combined fragmentation method (CFM) is a highly accurate computational tool for predicting NMR chemical shifts in small proteins.
- Incorporating nonbonded interactions is essential for achieving high accuracy in CFM-based NMR chemical shift calculations.
- CFM offers a promising approach for accurate and efficient NMR chemical shift prediction in computational chemistry and structural biology.
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