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Borcik CG, DeZonia B, Ravula T, Harding BD, Garg R, Rienstra CM. OPTO: Automated Optimization for Solid-State NMR Spectroscopy. J Am Chem Soc 2025; 147:3293-3303. [PMID: 39814553 PMCID: PMC11808819 DOI: 10.1021/jacs.4c13295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2025]
Abstract
NMR spectroscopy presents boundless opportunities for understanding the structure, dynamics, and function for a broad range of scientific applications. Solid-state NMR (SSNMR), in particular, provides novel insights into biological and material systems that are not amenable to other approaches. However, a major bottleneck is the extent of user training and the difficulty of obtaining reproducible, high-quality experimental results, especially for the sophisticated multidimensional pulse sequences that are essential to provide site-resolved measurements in large biomolecules. Here, we present OPTO, a software operating environment that addresses these challenges and enhances the performance of many types of commonly utilized SSNMR experiments. OPTO is compatible with Varian OpenVnmrJ and Bruker Topspin, with a front-end graphical user interface that presents the instrument operator with access to powerful underlying optimization algorithms, including simplex and grid searches of the dozens of parameter settings required for optimal performance. Therefore, OPTO efficiently leverages instrument time and enables instrument operators to find optimal experimental conditions reliably. We demonstrate examples including improvements in (1) resolution, with an automated, global search of 21 shimming parameters to achieve a 12 parts per billion line width; (2) sensitivity, with searches and refinements of several cross-polarization conditions dependent on 16 parameters in triple resonance experiments; and (3) robustness, with results from protein samples on several spectrometers operating at different magnetic field strengths and magic-angle spinning rates.
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Affiliation(s)
- Collin G. Borcik
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, 53706 USA
| | - Barry DeZonia
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, 53706 USA
| | - Thirupathi Ravula
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, 53706 USA
| | - Benjamin D. Harding
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI, 53706 USA
| | - Rajat Garg
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, 53706 USA
| | - Chad M. Rienstra
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706 USA
- National Magnetic Resonance Facility at Madison, University of Wisconsin-Madison, Madison, WI, 53706 USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53706 USA
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Porat-Dahlerbruch G, Struppe J, Polenova T. High-efficiency low-power 13C- 15N cross polarization in MAS NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 361:107649. [PMID: 38452523 PMCID: PMC11031345 DOI: 10.1016/j.jmr.2024.107649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 03/09/2024]
Abstract
Biomolecular solid-state magic angle spinning (MAS) NMR spectroscopy frequently relies on selective 13C-15N magnetization transfers, for various kinds of correlation experiments. Introduced in 1998, spectrally induced filtering in combination with cross polarization (SPECIFIC-CP) is a selective heteronuclear magnetization transfer experiment widely used for biological applications. At MAS frequencies below 20 kHz, commonly used for 13C-detected MAS NMR experiments, SPECIFIC-CP transfer between amide 15N and 13Cα atoms (NCA) is typically performed with radiofrequency (rf) fields set higher than the MAS frequency for both 13C and 15N channels, and high-power 1H decoupling rf field is simultaneously applied. Here, we experimentally explore a broad range of NCA zero-quantum (ZQ) SPECIFIC-CP matching conditions at the MAS frequency of 14 kHz and compare the best high- and low-power matching conditions with respect to selectivity, robustness, and sensitivity at lower 1H decoupling rf fields. We show that low-power NCA SPECIFIC-CP matching condition gives rise to 20% sensitivity enhancement compared to high-power conditions, in 2D NCA spectra of microcrystalline assemblies of HIV-1 CACTD-SP1 protein with inositol hexakis-phosphate (IP6).
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Affiliation(s)
- Gal Porat-Dahlerbruch
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States
| | - Jochem Struppe
- Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA 01821, United States
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States.
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