3.2. Circular Dichroism (CD) Spectroscopy

CD spectroscopy was used to evaluate the secondary structures of the peptides. The CD spectra of peptides were collected using a Jasco J-715 CD spectrophotometer (Jasco Inc., Tokyo, Japan), and their helical contents were determined from ellipticity at 222 nm, as described previously [20,32]. Briefly, the wavelength from 190 to 250 nm was measured at a speed of 50 nm/min, bandwidth of 1 nm, response time, and with a 0.1 nm step resolution. CD spectra were obtained in the presence and absence of PC/PC (1:1) liposomes (2 mM) at a peptide concentration of 25 μM.