Figure 5

Biophysical characterization of BslA orthologues. (A) Regime I times were measured using pendant drop tensiometry. Plotted is the mean of 4 separate repeat experiments and the error bars correspond to the standard deviation. (B) Wrinkles were formed in the protein films by compressing the pendant droplet via removal of fluid. The relaxation of these wrinkles are plotted as a function of time: Bs_BslA(black squares); Ba_BslA (blue triangles), Bl_BslA (red circles); Bp_BslA (green diamonds); YweA (orange stars). Error bars represent standard deviation in relaxation times for at least N = 10 separate wrinkles across the drop. (C) Inset in each image is the FFT contained within the white box. Ba_BslA visually showed ordered domains, but was not widespread.The FFT displays weak peaks indicating some ordering. (D) Bl_BslA has perceptibly larger domains of order. The FFT contains obvious peaks indicating ordering of the protein. (E) TEM of Bp_BslA films showed very weak ordering with patchy organization, which is reflected in the isotropic FFT. (F) YweA formed the ordered films that were the most similar to Bs_BslA, as can be seen from the FFT. (G) Solution state circular dichroism spectra of BslA variants and (H) circular dichroism spectra of RIMEs: Bs_BslA (black); Ba_BslA (blue); Bl_BslA (red); Bp_BslA (green); YweA (orange). Note the RIME CD spectra were normalized assuming all protein is adsorbed to emulsion droplets.