Fig. 5: Salt bridges decrease the unfolding rate of collagens.

A Decrease in the characteristic polyproline type II ellipticity signal of OGP, KGE, and KGD peptides after isothermal incubation at 37 °C. The initial CD spectra and after 8 h are shown in blue and yellow respectively. (B-C) Kinetics of unfolding of KGE and KGD peptides (B) and collagens type II, IV, and V at pH 2.5 (blue) and 7.0 (orange) (C). Residuals of the mono-exponential fit of collagen peptides and bi-exponential fit of native collagens are shown in Supplementary Fig. 7. D Kinetic stability comparison of OGP (gray), KGE (blue), and KGD (yellow) peptides analyzed by an Arrhenius plot derived from differential scanning calorimetry experiments performed at different scan rates. The line represents the best fit to the Arrhenius equation. Kinetic parameters are shown in Table 1. DSC endotherms and fitting to a two-state kinetic model are shown in Supplementary Fig. 8.