Raman spectroscopic determination of the secondary structure of crystalline nerve growth factor.

The secondary structure of crystalline nerve growth factor (NGF) has been measured with 90% confidence to contain between 0 and 11% helix and between 53 and 67% antiparallel beta-strand using the intensity distribution of the amide I region of the Raman spectrum. A comparison of spectra collected from crystals and solutions confirms that the secondary structure of NGF is the same in these two states. The helical content of NGF as determined by Raman differs substantially from predictions based on sequence. The amide I band of NGF is substantially different from that of insulin, indicating that no structural hemology is likely to exist between these two proteins.