Summary plot of the results from the HDX pulse labeling experiments showing similar intermediate structure for WT and permutant proteins PM23, PM65, and PM142.

<p>Molecular and linear representations of IL-1β and permutants indicating β-strands involved in early folding events for all protein variants. The strands of the proteins protected early in the refolding (28 msec) reaction are colored in green for clarity. Purple and cyan highlight the functional loops, the 90′s loop and β-bulge, respectively. Red spheres represent the new termini. For all proteins, the β-strands within the functional route shows similar early protection in refolding. PM76 is not shown, as the protein variant was not amenable to these experimental conditions (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038512#s4" target="_blank">material and methods</a>).