Circular dichroism spectroscopy has intrinsic limitations for protein secondary structure analysis

Secondary structure content (SSC) cannot be calculated accurately from circular dichroism (CD) spectra for the majority of proteins whose three-dimensional structures have been solved. Reliable SSC that is significantly different from random SSC can be calculated from CD spectra only for all-alpha proteins and all-P proteins with canonical beta-strand geometry. (C) 2009 Elsevier Inc. All rights reserved.