Frequency-Switched Single-Transition Cross-Polarization: A Tool for Selective Experiments in Biomolecular NMR

• Published in: Chemphyschem Vol. 5; no. 1; pp. 76 - 84
• Main Authors: Ferrage, Fabien, Eykyn, Thomas R., Bodenhausen, Geoffrey
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 23.01.2004; WILEY‐VCH Verlag; Wiley
• Subjects: Biological and medical sciences; Carbon Isotopes; cross-polarization; Fundamental and applied biological sciences. Psychology; General aspects, investigation technics, apparatus; indirect relaxation measurements; Models, Theoretical; Nitrogen Isotopes; NMR spectroscopy; Nuclear Magnetic Resonance, Biomolecular - methods; Nucleic Acids - chemistry; proteins; Proteins - chemistry; Quantum Theory; selective excitation; Tissues, organs and organisms biophysics; Cross polarization; NMR spectrometry; Protein; Two dimension spectrometry; Nuclear Overhauser effect; Spin relaxation; indirect relaxation measurements; cross-polarization; proteins; selective excitation; NMR spectroscopy; Nucleic acid; Pulse sequence
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.200300905

Frequency‐switched single‐transition cross‐polarization (FS‐ST‐CP) provides a versatile tool for selective coherence transfer in heteronuclear NMR of biomolecules such as proteins and nucleic acids. This type of coherence transfer is spin‐state‐selective and can therefore benefit from the extension of the life‐times of selected coherences due to partial cancellation of interfering relaxation mechanisms. The limits of the selectivity of the transfer are discussed by theory and illustrated by experiment. The methods are particularly efficient to obtain quantitative structural and dynamic information for selected residues in medium‐sized nitrogen‐15 or carbon‐13 labeled macromolecules. Protein NMR: A selective NMR scheme called frequency‐switched single‐transition cross‐polarization (FS‐ST‐CP) is applied to study biological macromolecules. Structural and dynamic information concerning a single amino acid may be extracted by selecting relevant signals such as those of leucine 73 in the protein ubiquitin (magnified).