Ir sse analytical software

The IR spectral measurement was performed using IRT-7000 infrared microscope (Jasco Co, Tokyo, Japan) and FT/IR-6100 spectrometer (Jasco Co., Tokyo, Japan). The infrared spectra were recorded by a reflection mode from several areas on the dry surface of the peptide film with 64 scans and 4 cm⁻¹ resolution, and the morphology of the peptide film was observed by 16x Cassegrain lens. The obtained spectral data were transformed into text files, and those absorption intensities at a range of wavenumbers from 1000 to 4000 cm⁻¹ were averaged followed by re-converting to infrared spectral trace.
For protein secondary structure analysis, we used IR-SSE analytical software (Jasco Co., Tokyo, Japan). In this program, a calibration curve was prepared prior to multicomponent analysis (Partial Least Squares quantification model) based on the secondary-structural data of 17 proteins, and it was saved as a standard data file^{23 (link)}. The amide I band was deconvoluted into major four bands: α-helix (1650–55 cm⁻¹), β-sheet (1625–40 cm⁻¹), β-turn (1655–75 cm⁻¹), and non-ordered (other) conformation (1645–50 cm⁻¹). Proportions of secondary structures were calculated using peak intensities at those amide-I bands in the averaged IR spectrum.

For estimation of the proportions of the peptide conformations, IR-SSE analytical software (Jasco Co.) was used (Sarver & Krueger, 1991 ▸ ). The amide I band observed between 1600 and 1700 cm⁻¹ can be divided into four bands: α-helix (1650–55 cm⁻¹), β-sheet (1625–40 cm⁻¹), turn (1655–75 cm⁻¹) and non-ordered conformation (1645–50 cm⁻¹), and the proportion of the conformation was obtained from the ratio of the peak intensity of each conformation to that of the whole amide I band. Those data were statistically analysed using several peptide samples before or after the irradiations.