Previously, Conticello and colleagues characterized an elastin-mimetic protein of the similar composition [(VPGVG)4(VPGKG)]39 This polymer, which has overall fewer repeats and higher charge density than KI8, displayed a strong pH-dependence of transition temperature (Tt). To investigate the pH-and ionic-strength dependence of the LCST of KI8, we performed temperature-dependent DLS from 4 -40 °C in the same four different solution conditions used for the concentration series above, at a concentration of 0.4 mg/mL (10 µM) KI8 (Figures ). We predicted that at the lower pH, the greater charge on KI8 would increase its Tt compared to the lower pH at each salt concentration. Surprisingly, we observed no difference in Tt across dependent transition temperatures in 50-140 mM NaCl. We hypothesize that this difference 179 may be attributed to the lower linear charge density of KI8, leading to greater susceptibility to screening effects. We can also compare this result to a recent systematic study of acidic pHresponsive ELPs of varying length and composition. The authors of this study also find that some of their ELPs are pH-insensitive under certain conditions despite having many ionizable residues. The authors also found that higher [NaCl] did not always decrease Tt, but in at least one case increased it, perhaps via a salting-in effect. This supports the conclusion that the effect of salt and pH on ELP solubility are highly sequence dependent.