Squeezing out the secondary structure information of proteins: a combined circular dichroism infrared-spectroscopy approach

Mid-infrared (IR) spectroscopy and electronic circular dichroism (ECD) spectroscopy are well-established, complementary techniques that can be used to study protein structure and denaturation. Attempts have been made to combine them in the past using chemometrics. In this work we try to combine the techniques using multivariate curve resolution- alternating least squares (MCR-ALS). To this end, we simulate IR and ECD spectra to first demonstrate the effect of concentration on these spectra and subsequently analyze them, first separately and then together, using MCR-ALS. The results show that a modified version of MCR-ALS, capable of dealing with missing data while still being able to use the benefits of having information from two different techniques would be the correct choice for the given problem, especially when layers of complexity are added with measured data in the future.