title: On the reliability of NMR relaxation data analyses: a Markov Chain Monte Carlo approach.
abstract: The analysis of NMR relaxation data is revisited along the lines of a Bayesian approach. Using a Markov Chain Monte Carlo strategy of data fitting, we investigate conditions under which relaxation data can be effectively interpreted in terms of internal dynamics. The limitations to the extraction of kinetic parameters that characterize internal dynamics are analyzed, and we show that extracting characteristic time scales shorter than a few tens of ps is very unlikely. However, using MCMC methods, reliable estimates of the marginal probability distributions and estimators (average, standard deviations, etc.) can still be obtained for subsets of the model parameters. Thus, unlike more conventional strategies of data analysis, the method avoids a model selection process. In addition, it indicates what information may be extracted from the data, but also what cannot.
authors.affiliation: Ecole Normale Supérieure, Departement de Chimie, UMR 7203 CNRS-UPMC-ENS, 24, rue Lhomond, 75005 Paris, France. Electronic address: daniel.abergel@ens.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Abergel
authors.affiliation: Padua University - Department of Chemical Sciences, Via Marzolo 1, 35131 Padua, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Volpato
authors.affiliation: Ecole Normale Supérieure, Departement de Chimie, UMR 7203 CNRS-UPMC-ENS, 24, rue Lhomond, 75005 Paris, France.
authors.forename: Eloi P
authors.initials: EP
authors.lastname: Coutant
authors.affiliation: Padua University - Department of Chemical Sciences, Via Marzolo 1, 35131 Padua, Italy. Electronic address: antonino.polimeno@unipd.it.
authors.forename: Antonino
authors.initials: A
authors.lastname: Polimeno
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008390:Markov Chains; D015233:Models, Statistical; D009010:Monte Carlo Method; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Bayes theorem; Fractional Brownian dynamics; Markov chains; NMR; Protein dynamics; Relaxation; SRLS