Detection of residue contacts in a protein folding intermediate.
Proc Natl Acad Sci U S A 94:14 (1997) 7182-7185
Abstract:
Protein folding can be described in terms of the development of specific contacts between residues as a highly disordered polypeptide chain converts into the native state. Here we describe an NMR based strategy designed to detect such contacts by observation of nuclear Overhauser effects (NOEs). Experiments with alpha-lactalbumin reveal the existence of extensive NOEs between aromatic and aliphatic protons in the archetypal molten globule formed by this protein at low pH. Analysis of their time development provides direct evidence for near-native compactness of this state. Through a rapid refolding procedure the NOE intensity can be transferred efficiently into the resolved and assigned spectrum of the native state. This demonstrates the viability of using this approach to map out time-averaged interactions between residues in a partially folded protein.Characterisation of protein unfolding by NMR diffusion measurements
Journal of Biomolecular NMR 10:2 (1997) 199-203
Abstract:
The characterisation of non-native states of proteins is a key problem in studies of protein folding. Complete characterisation of these states requires a description of both local and global properties, including molecular dimensions. Here we present results from pulsed field gradient experiments designed to compare the effective hydrodynamic radii of a protein in native and non-native states. Measurements performed on lysozyme indicate that the effective hydrodynamic radius increases by 38±1% on unfolding in urea, a result completely consistent with a recent study by small-angle X-ray scattering.Geometric dephasing in zero-field magnetic resonance
JOURNAL OF CHEMICAL PHYSICS 106:8 (1997) 3007-3016
Optimal sampling strategies for the measurement of relaxation times in proteins
JOURNAL OF MAGNETIC RESONANCE 126:2 (1997) 283-286
Optimal sampling strategies for the measurement of spin-spin relaxation times
Journal of Magnetic Resonance - Series B 113:1 (1996) 25-34