Repository logo
 

Structure-Free Validation of Residual Dipolar Coupling and Paramagnetic Relaxation Enhancement Measurements of Disordered Proteins.


Type

Article

Change log

Authors

Newby, Francisco N 
De Simone, Alfonso 
Yagi-Utsumi, Maho 
Salvatella, Xavier 
Dobson, Christopher M 

Abstract

Residual dipolar couplings (RDCs) and paramagnetic relaxation enhancements (PREs) have emerged as valuable parameters for defining the structures and dynamics of disordered proteins by nuclear magnetic resonance (NMR) spectroscopy. Procedures for their measurement, however, may lead to conformational perturbations because of the presence of the alignment media necessary for recording RDCs, or of the paramagnetic groups that must be introduced for measuring PREs. We discuss here experimental methods for quantifying these effects by considering the case of the 40-residue isoform of the amyloid β peptide (Aβ40), which is associated with Alzheimer's disease. By conducting RDC measurements over a range of concentrations of certain alignment media, we show that perturbations arising from transient binding of Aβ40 can be characterized, allowing appropriate corrections to be made. In addition, by using NMR experiments sensitive to long-range interactions, we show that it is possible to identify relatively nonperturbing sites for attaching nitroxide radicals for PRE measurements. Thus, minimizing the conformational perturbations introduced by RDC and PRE measurements should facilitate their use for the rigorous determination of the conformational properties of disordered proteins.

Description

Keywords

Amyloid beta-Peptides, Electron Spin Resonance Spectroscopy, Humans, Intrinsically Disordered Proteins, Models, Molecular, Nuclear Magnetic Resonance, Biomolecular, Peptide Fragments, Protein Conformation, Recombinant Proteins, Spin Labels

Journal Title

Biochemistry

Conference Name

Journal ISSN

0006-2960
1520-4995

Volume Title

54

Publisher

American Chemical Society (ACS)
Sponsorship
Engineering and Physical Sciences Research Council (EP/K039520/1)