Effects of amino acid phi,psi propensities and secondary structure interactions in modulating H alpha chemical shifts in peptide and protein beta-sheet.
H alpha chemical shifts are often used as indicators of secondary structure formation in protein structural analysis and peptide folding studies. On the basis of NMR analysis of model beta-sheet and alpha-helical peptides, together with a statistical analysis of protein structures for which NMR data are available, we show that although the gross pattern of H alpha chemical shifts reflects backbone torsion angles, longer range effects from distant amino acids are the dominant factor determining experimental chemical shifts in beta-sheets of peptides and proteins. These show context-dependent variations that aid structural assignment and highlight anomalous shifts that may be of structural significance and provide insights into beta-sheet stability.
Sharman
G J
GJ
AstraZeneca, Silk Road Business Park, Macclesfield, Cheshire SK10 2NA, UK.
Griffiths-Jones
S R
SR
Jourdan
M
M
Searle
M S
MS
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D006860:Hydrogen Bonding; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010446:Peptide Fragments / Q000737:chemistry; D017433:Protein Structure, Secondary; D025801:Ubiquitin / Q000737:chemistry
D000596:Amino Acids; D010446:Peptide Fragments; D025801:Ubiquitin