2.2. Fluorescence spectroscopy
Fluorescence spectroscopy was used to monitor the conformational changes in the DPs (Mw < 5 kDa) after the addition of calcium with a Hitachi F-4600 spectrofluorimeter (Hitachi, Japan). The monitoring time was 120 s and the experimental temperature was 20 °C. The spectra at an excitation wavelength of 315 nm and an emission wavelength between 300 and 500 nm were recorded.