The 13C chemical-shift index: a simple method for the identification of protein secondary structure using 13C chemical-shift data

J Biomol NMR. 1994 Mar;4(2):171-80. doi: 10.1007/BF00175245.


A simple technique for identifying protein secondary structures through the analysis of backbone 13C chemical shifts is described. It is based on the Chemical-Shift Index [Wishart et al. (1992) Biochemistry, 31, 1647-1651] which was originally developed for the analysis of 1H(alpha) chemical shifts. By extending the Chemical-Shift Index to include 13C(alpha), 13C(beta) and carbonyl 13C chemical shifts, it is now possible to use four independent chemical-shift measurements to identify and locate protein secondary structures. It is shown that by combining both 1H and 13C chemical-shift indices to produce a 'consensus' estimate of secondary structure, it is possible to achieve a predictive accuracy in excess of 92%. This suggests that the secondary structure of peptides and proteins can be accurately obtained from 1H and 13C chemical shifts, without recourse to NOE measurements.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / analysis
  • Carbon Isotopes
  • Interferon-gamma / chemistry*
  • Magnetic Resonance Spectroscopy / methods*
  • Protein Structure, Secondary*
  • Solvents


  • Amino Acids
  • Carbon Isotopes
  • Solvents
  • Interferon-gamma