title: A (15)N CPMG relaxation dispersion experiment more resistant to resonance offset and pulse imperfection.
abstract: Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion is a powerful NMR method to study protein dynamics on the microsecond-millisecond time scale. J-coupling, resonance offset, radio frequency field inhomogeneity, and pulse imperfection often introduce systematic errors into the measured transverse relaxation rates. Here we proposed a modified continuous wave decoupling CPMG experiment, which is more unaffected by resonance offset and pulse imperfection. We found that it is unnecessary to match the decoupling field strength with the delay between CPMG refocusing pulses, provided that decoupling field is strong enough. The performance of the scheme proposed here was shown by simulations and further demonstrated experimentally on a fatty acid binding protein.
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, 430071 Wuhan, China. Electronic address: jbin@wipm.ac.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore.
authors.forename: Binhan
authors.initials: B
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, 430071 Wuhan, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, 430071 Wuhan, China. Electronic address: ml.liu@wipm.ac.cn.
authors.forename: Maili
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore. Electronic address: dbsydw@nus.edu.sg.
authors.forename: Daiwen
authors.initials: D
authors.lastname: Yang
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004574:Electromagnetic Fields; D050556:Fatty Acid-Binding Proteins / Q000737:chemistry; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D050556:Fatty Acid-Binding Proteins; D011506:Proteins
keywords: CPMG; Conformational exchange; Protein dynamics; Relaxation dispersion