Guilhem Pagès1,2, Philip W Kuchel3. 1. Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore. 2. Currently at: Groupe de RMN Biomédicale, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, UMR CNRS 5068, Université de Toulouse, 118 route de Narbonne, 31062 Toulouse cedex, France. 3. School of Molecular Bioscience, University of Sydney, Sydney, New South Wales, Australia.
Abstract
PURPOSE: To introduce a direct method for estimating relaxation and kinetic parameter values from rapid dissolution dynamic nuclear polarization (RD-DNP) NMR time courses. THEORY AND METHODS: The analysis relied on a kinetic model that is often used to analyze data in these studies-a unidirectional (bio)chemical reaction with rate constant k1 , coupled to longitudinal relaxation of the magnetization of substrate and product that is characterized by the time constant T1 . The latter value was estimated from the width of the product curve (peak) at the height α relative to the maximum height. We showed α ∼ 0.8 under most conditions, so we measured the interval between the falling and rising parts of the curve at the relative height 0.8. We called this the "fall-minus-rise time at height α," or FmRα , and found that FmR0.8 ∼ T1 . The ratio β = (product signal/substrate signal) when the product is maximal was shown to be equal to k1 T1 . Therefore, k1 = β/FmR0.8 . RESULTS: FmRα analysis was demonstrated with (13) C NMR RD-DNP data recorded from hemolysates and from previously published data. CONCLUSION: FmRα analysis enables immediate estimates of kinetic and relaxation parameters from (13) C NMR RD-DNP data. The values can be used as initial estimates in more extensive computer-based data-regression analysis.
PURPOSE: To introduce a direct method for estimating relaxation and kinetic parameter values from rapid dissolution dynamic nuclear polarization (RD-DNP) NMR time courses. THEORY AND METHODS: The analysis relied on a kinetic model that is often used to analyze data in these studies-a unidirectional (bio)chemical reaction with rate constant k1 , coupled to longitudinal relaxation of the magnetization of substrate and product that is characterized by the time constant T1 . The latter value was estimated from the width of the product curve (peak) at the height α relative to the maximum height. We showed α ∼ 0.8 under most conditions, so we measured the interval between the falling and rising parts of the curve at the relative height 0.8. We called this the "fall-minus-rise time at height α," or FmRα , and found that FmR0.8 ∼ T1 . The ratio β = (product signal/substrate signal) when the product is maximal was shown to be equal to k1 T1 . Therefore, k1 = β/FmR0.8 . RESULTS: FmRα analysis was demonstrated with (13) C NMR RD-DNP data recorded from hemolysates and from previously published data. CONCLUSION: FmRα analysis enables immediate estimates of kinetic and relaxation parameters from (13) C NMR RD-DNP data. The values can be used as initial estimates in more extensive computer-based data-regression analysis.
Authors: Alexander Kirpich; Mukundan Ragavan; James A Bankson; Lauren M McIntyre; Matthew E Merritt Journal: J Chem Inf Model Date: 2019-01-15 Impact factor: 4.956
Authors: Charlie J Daniels; Mary A McLean; Rolf F Schulte; Fraser J Robb; Andrew B Gill; Nicholas McGlashan; Martin J Graves; Markus Schwaiger; David J Lomas; Kevin M Brindle; Ferdia A Gallagher Journal: NMR Biomed Date: 2016-01-18 Impact factor: 4.044
Authors: Dmitry Shishmarev; Philip W Kuchel; Guilhem Pagès; Alan J Wright; Richard L Hesketh; Felix Kreis; Kevin M Brindle Journal: Commun Biol Date: 2018-12-21