3.16.1. Circular Dichroism (CD)

*CD spectra* were recorded on Chirascan Plus CD spectrometer (Applied Photophysics, UK) in quartz cuvettes with an optical path length of 0.1 and 1 cm for the far-UV, or peptide for the near-UV or aromatic regions. The measurements were performed at room temperature (22 ◦C). Protein solutions in urea and detergent were centrifuged at 15,000× *g* for 20 min before taking the spectra. The presented data are the average of two independent measurements, each averaged of three scans. Each averaged CD spectrum was corrected for the buffer baseline by subtracting an averaged buffer CD signal over the same wavelength region. The content of the secondary structure elements in the recombinant proteins was calculated according to Sreerama method from software package CD*Pro* [31].
