Figure 2. Fluorescent βTail fusion proteins stably integrate into Q11 nanofibers and microgels in smoothly gradated amounts, alone or in combination, without loss of activity.

a) Fluorescent βT fusion proteins integrated into Q11 nanofibers over the range of 0.25-1.5 μM in a βTail-dependent manner, as measured by loss of fluorescence from the supernatant. b) βT-GFP integrated into micron-sized Q11 “microgels” in a βTail- dependent manner. c-d) Fluorescent βTail fusion proteins integrated into Q11 microgels at a predictable dose. e) Different fluorescent βTail proteins co-integrated into Q11 microgels at a precisely tunable dose, as demonstrated by the close correlation between actual gel color and the predicted color, which was determined by using the protein mole ratio in solution during assembly as the RGB pixel ratio. f-g) GFP fluorescence was retained in Q11 microgels when diluted 0-100 fold in 1× PBS, suggesting the materials were in a “kinetically-trapped” state. h-i) Fluorescence intensity of Q11 microgels with βTail-GFP proteins was similar at different time points, demonstrating the stability of these materials. N = 3 for a; N = 5 for g; and N = 10 for d and i. mean ± s.d. Scale bar = 40 μm in b, c, e, f, and h.