Identification of partially disordered peptide intermediates through residue-specific NMR diffusion measurements.
It is technically challenging to detect low-population partially disordered species that are in equilibrium with the folded and unfolded states. Residue-specific translational diffusion experiments measured by pulsed field gradient NMR have been used to detect the presence, and define the conformation, of such equilibrium intermediates. The experiment is demonstrated for equilibrium solutions of related triple helical peptides that model a small region of type I collagen with and without a mutation known to cause osteogenesis imperfecta. The data show that residue-specific diffusion coefficients of an interconverting trimer to monomer system can allow discrimination between a simple two-state model and more complex multistate models involving partially disordered intermediates.
Li
Yingjie
Y
Department of Chemistry, Rutgers University, Piscataway, New Jersey 08854, USA.
Kim
Seho
S
Brodsky
Barbara
B
Baum
Jean
J
D000595:Amino Acid Sequence; D024042:Collagen Type I / Q000737:chemistry*; D004058:Diffusion; D007700:Kinetics; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary
D024042:Collagen Type I; D010455:Peptides