"Extracting Markov models of peptide conformational dynamics from simulation data" Verena Schultheis, Thomas Hirschberger, Heiko Carstens, and Paul Tavan
J. Chem. Theory Comput. 1, 515  526 (2005).
Abstract: A highdimensional time series obtained by simulating a complex and stochastic dynamical system (like a peptide in solution) may code an underlying multiplestate Markov process. We present a computational approach to most plausibly identify and reconstruct this process from the simulated trajectory. Using a mixture of normal distributions we first construct a maximum likelihood estimate of the point density associated with this time series and thus obtain a densityoriented partition of the data space. This discretization allows us to estimate the transfer operator as a matrix of moderate dimension at
sufficient statistics. A nonlinear dynamics involving that matrix and, alternatively, a deterministic coarsegraining procedure are employed to construct respective hierarchies of Markov models, from which the model most
plausibly mapping the generating stochastic process is selected by consideration of certain observables. Within both procedures the data are classified in terms of prototypical points, the conformations, marking the various Markov states. As a typical example, the approach is applied to analyze the conformational dynamics of a tripeptide in solution. The corresponding highdimensional time series has been obtained from an extended molecular dynamics simulation.
BMO authors (in alphabetic order): Heiko Carstens Thomas Hirschberger Verena Schultheis Paul Tavan
Assoziierte Projekte: Selforganized pattern classification and its application to molecular structures
