Comparison of spectroscopic techniques for determination of protein secondary structure

Determination of the protein secondary structure is a key task in academic and industrial fields related to biotechnology and the pharmaceutical sciences. Spectroscopic techniques offer the potential for rapid estimation of individual shares of secondary structures. In this work, 17 model proteins with known secondary structure were analysed by infrared (IR), Raman, far-UV circular dichroism (CD) spectroscopy and polarimetry. The recorded spectra were evaluated using PLS analysis (IR, Raman) and multiple dedicated algorithms (far-UV CD). Resulting figures of merit were compared and the application parameters of each spectroscopic technique were discussed. The best results were obtained from PLS models of IR and Raman spectra for the estimation of α-helix and β-sheet secondary structures. Far-UV CD spectroscopy combined with the CONTINLL algorithm achieved good figures of merit for α-helix and β-sheet. Polarimetry was shown to give good results for the analysis of α-helix.