2.10. Dynamic light scattering (DLS) measurements

The change in aggregation comportment of CA in the different conditions was determined using DLS. For the R_h measurements the protein concentration was taken as 15 μM at 830 nm on a DynaPro–TC–04 dynamic light scattering instrument (Protein Solutions, Wyatt Technology, Santa Barbara, CA) equipped with a temperature controlled microsampler. Prior to the measurements all the solutions were filtered through a 0.22 μm pore sized microfilter (Whatman International, Maidstone, UK). The measured hydrodynamic radius (R_h) was the average of 50 measurements. The mean R_h and polydispersity (Pd) were estimated, on the basis of an autocorrelation analysis of scattered light intensity based on the translational diffusion coefficient, from the Stokes–Einstein Eq. (2)

where, R_h is the hydrodynamic radius, k is the Boltzmann’s constant, T is the absolute temperature, η is the viscosity of water and DW25°C is the translational diffusion coefficient. All the samples were incubated for 60 min at 65 °C preceding to the measurements.