BIOCHEMISTRY. For the article “Heterogeneity in EGF-binding affinities arises from negative cooperativity in an aggregating system,” by Jennifer L. Macdonald and Linda J. Pike, which appeared in issue 1, January 8, 2008, of Proc Natl Acad Sci USA (105:112–117; first published December 28, 2007; 10.1073/pnas.0707080105), the authors note that in Fig. 3, in the parameter list inset at lower right, the labels K21 and L20 are reversed. The correct values for all four parameters are K11 = 4.6 ± 0.6 × 109, L20 = 5.3 ± 2.2 × 1011, K21 = 5.3 ± 0.4 × 109, and K22 = 3.4 ± 1.1 × 108. This error does not affect the conclusions of the article. The corrected figure and its legend appear below.
Fig. 3.
Binding of EGF to cells expressing increasing levels of wild-type EGF receptors. CHO-K1 tet-on EGFR cells were induced to express EGF receptors by using increasing doses of doxycycline. 125I-EGF-binding isotherms were generated from each set of cells, and all six isotherms were globally fit to Eq. 1, with only the value of R0 varying among curves. Data points represent the mean ± SD of triplicate determinations. Solid lines represent the fitted curve through the data points of the same color.