Dts version 4

The homogeneity of solutions, the aggregation state and particle sizes were analyzed by granulometry on a Zetasizer Nano-S model (Malvern Instruments, Malvern, UK). The protein solution was analyzed by DLS at a final concentration of 4mg/ml either in 50 mM phosphate buffer pH8.0 or 30 mM Tris-HCl, 200 mM NaCl buffer. The supernatant of each sample was gently transferred into a quartz cuvette of 12 µl and the particle size measurements were performed in triplicate at 37°C, with alight diffusion at 173°. The data were collected in automatic mode and analyzed using the associated software DTS version 4.2 (Malvern Instruments).

The particle size determination of bile salt micelles and potentially, peptide aggregates was performed by granulometry on a Zetasizer Nano-S model (Malvern Instruments, Malvern, UK).
Each pure peptide was analyzed by DLS at final concentrations of 3.3 µM for INYW and 1.7 µM for LQKW and LDQW, either in TBS buffer or in ultra-pure water alone or in the presence of 0.1% trifluoroacetic acid. Each pure bile salt was also analyzed by DLS at final concentration of 50 mM in TBS buffer. Each peptide/bile salt mixture was prepared in TBS buffer, by taking the same final concentrations as above. Prior to the DLS investigations, all samples were centrifuged at 21,130 g for 30 min at 37 °C to eliminate dust or undesired particles having hydrodynamic diameter higher than 1000 nm that could interfere the measure. The supernatant of each sample was gently transferred into a quartz cuvette of 12 µl and the particle size measurements were performed in triplicate at 37 °C, with a light diffusion at 173°. The data were collected in automatic mode and analyzed using the associated software DTS version 4.2 (Malvern Instruments).