Given its low apparent Tt, subsequent I90 experiments were performed at 0.1 mg/mL. Still, in both 10 mM HEPES pH 7.4, 15 mM NaCl and 10 mM CAPS pH 11.2, 15 mM NaCl conditions, I90 began to coacervate at 6-8 °C, continued to assemble to 200-500 nm particles, then jumped to 1.5-2 µm diameter particles above 30 °C. There are several comparisons one can make between KI8 and I90 LCST behaviors. First, both I90 in water and KI8 in 0.1 NaOH transition around 6-8 °C, with very similar temperature trend profiles. This supports the validity of considering KI8 at high pH to be fully deprotonated. Second, I90 shows no difference in Tt with changing pH/buffer conditions, an expected result as it does not contain any ionizable residues. However, in both buffered, low-salt conditions, I90 was much less soluble than KI8, even at a lower protein concentration.