Open AccessInfluence of the coupling of interdomain and overall motions on NMR relaxation
Author(s) -
Vance Wong,
David A. Case,
Attila Szabó
Publication year - 2009
Publication title -
proceedings of the national academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0809994106
Subject(s) - conformational isomerism , rotational diffusion , relaxation (psychology) , rotation around a fixed axis , diffusion , statistical physics , formalism (music) , diffusion mri , physics , coupling (piping) , jump , chemistry , classical mechanics , molecule , nuclear magnetic resonance , thermodynamics , materials science , quantum mechanics , magnetic resonance imaging , medicine , psychology , social psychology , musical , art , radiology , metallurgy , visual arts
Most theoretical models for NMR relaxation in liquids assume that overall rotational motion can be described as rotational diffusion with a single diffusion tensor. Such models cannot handle motions (such as between "closed" and "open" states of an enzyme, or between conformers of a partially disordered system) where the shape of the molecule (and hence its rotational diffusion behavior) fluctuates. We provide here a formalism for dealing with such problems. The model involves jumps between discrete conformers with different overall diffusion tensors, and a master (rate) equation to describe the transitions between these conformers. Numerical examples are given for a two-site jump model where global and local motions are concerted, showing how the rate of conformational transitions (relative to the rate of rotational diffusion) affects the observed relaxation parameters.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom