Direct measure of cooperativity in DM-mediated peptide association.

<p>(a) Association rate of peptides to DR1 in the presence of DM was measured as described in Results. Data is plotted as the fraction of either peptide or DR1 forming complex. Reactions were performed in triplicate, and data points represent one of three independent experiments. Error bars are omitted for graphic clarity. Lines fit the data to a four parameter double exponential function. (b) Natural log (ln) plot of cooperativity (expected/observed <i>K</i>_eq) vs. association rate for each peptide tested. Error bars are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003722#pone-0003722-g001" target="_blank">figure 1b</a>. The line indicates the fit of the data to a linear regression.