An Effective Method for the Discrimination of Motional Anisotropy and Chemical Exchange
- 6 February 2002
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 124 (9) , 1852-1853
- https://doi.org/10.1021/ja017461k
Abstract
Analysis of the ratio of transverse and longitudinal relaxation rates (R2/R1) is an approach commonly used for estimation of overall correlation time and identification of chemical exchange in biological macromolecules. However, this analysis fails to distinguish between chemical exchange and motional anisotropy. We describe a simple method for identifying chemical exchange and motional anisotropy using the product, R1R2. In the slow tumbling regime, the R1R2 product results in a constant value that is independent of overall correlation time and motional anisotropy. This analysis provides a simple method for rapidly estimating and dissociating the effects of motional anisotropy and chemical exchange in NMR heteronuclear spin relaxation data. We demonstrate the utility of the method with 15N relaxation data collected on the proteins E. coli ribonuclease H and the trimeric E. coli membrane associated lipoprotein lpp.Keywords
This publication has 12 references indexed in Scilit:
- Variability of the 15N Chemical Shift Anisotropy in Escherichia coli Ribonuclease H in SolutionJournal of the American Chemical Society, 1999
- The Use of Residual Dipolar Coupling in Concert with Backbone Relaxation Rates to Identify Conformational Exchange by NMRJournal of the American Chemical Society, 1999
- A Relaxation-Compensated Carr−Purcell−Meiboom−Gill Sequence for Characterizing Chemical Exchange by NMR SpectroscopyJournal of the American Chemical Society, 1999
- Temperature dependence of intramolecular dynamics of the basic leucine zipper of GCN4: implications for the entropy of association with DNAJournal of Molecular Biology, 1999
- Longitudinal and Transverse 1H−15N Dipolar/15N Chemical Shift Anisotropy Relaxation Interference: Unambiguous Determination of Rotational Diffusion Tensors and Chemical Exchange Effects in Biological MacromoleculesJournal of the American Chemical Society, 1998
- Protein dynamics from NMRNature Structural & Molecular Biology, 1998
- Monitoring Macromolecular Motions on Microsecond to Millisecond Time Scales by R1ρ−R1 Constant Relaxation Time NMR SpectroscopyJournal of the American Chemical Society, 1996
- Backbone Dynamics of Ribonuclease HI: Correlations with Structure and Function in an Active EnzymeJournal of Molecular Biology, 1995
- A Test of the Model-Free Formulas. Effects of Anisotropic Rotational Diffusion and DimerizationJournal of Magnetic Resonance, Series B, 1994
- Spin Relaxation Processes in a Two-Proton System Undergoing Anisotropic ReorientationThe Journal of Chemical Physics, 1962