Fig. 5. The locked-trimeric mutant MIF^N110C completely suppresses amyloid fibril formation of the mutant SOD1.

a Experimental protocol used for determining whether purified recombinant MIF^WT or MIF mutants suppress the amyloid aggregation of misfolded SOD1, as detected by ThT and TEM . b ThT fluorescence was monitored during the incubation (37 °C with continuous shaking) of mutant SOD1^G93A(50 µM), either without (black) or with recombinant MIF^WT (red), MIF^C60S (blue), MIF^P2A(pink), or MIF^N110C(green), all at a 10 µM concentration. Fluorescence was normalized to the maximal ThT fluorescence intensity that was elicited by SOD1^G93A alone. Data indicate the average of 30–50 replicates performed from three independent experiments. Fluorescence was fitted to Boltzmann sigmoidal equation using OriginPro 8.5 software. c TEM images of a SOD1^G93A (50 µM) solution after a 68-h incubation at 37 °C with continuous shaking. SOD1^G93A was incubated in the presence of recombinant MIF^C60S, MIF^P2A, or MIF^N110C at a molar ratio of 5:1.