title: Secondary Structure Assignment of Amyloid-β Peptide Using Chemical Shifts.
abstract: The distinct conformational dependence of chemical shifts caused by α-helices and β-sheets renders NMR chemical shift analysis a powerful tool for the structural determination of proteins. However, the time scale of NMR experiments can make a secondary structure assignment of highly flexible peptides or proteins, which may be converting between conformational substates, problematic. For instance the amyloid-β monomer, according to NMR chemical shifts, adopts a predominately random coil structure in aqueous solution (with <3% α-helical content). Molecular dynamics simulations, on the other hand, suggest that α-helical content can be significant (10-25%). In this paper, we explore the possible reasons for this discrepancy and show that the different results from experiments and theory are not necessarily mutually exclusive but may reflect a general problem of secondary structure assignment of conformationally flexible biomolecules.
authors.affiliation: Laboratory of Computational Chemistry and Biochemistry, BCH 4107 EPF Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Geoffrey P F
authors.initials: GP
authors.lastname: Wood
authors.affiliation: Laboratory of Computational Chemistry and Biochemistry, BCH 4107 EPF Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Ursula
authors.initials: U
authors.lastname: Rothlisberger