CD spectra were acquired on a Jasco J815 spectropolarimeter at 25 °C (Peltier), using 0.1 mm quartz cells, 1 s integration, stepsize of 0.5 nm, 1 nm bandwidth, and 25 accumulations. The dipeptides were dissolved at 1 mM in milliQ water, and the pH was adjusted to 7.0 by adding NaOH (1 M) dropwise.