BIOPHYSICS. For the article “A quantitative assessment of models for voltage-dependent gating of ion channels,” by Michael Grabe, Harold Lecar, Yuh Nung Jan, and Lily Yeh Jan, which appeared in issue 51, December 21, 2004, of Proc. Natl. Acad. Sci. USA (101, 17640-17645; first published December 10, 2004; 10.1073/pnas.0408116101), the authors note that Fig. 3a was computed with a tilt angle different from that detailed in the Results. The corrected curves, presented below, are ≈7% smaller in magnitude than the curves presented in Fig. 3a Left, but their shape and spacing are preserved. The correction will not alter the curve shown in Fig. 3a Right. The corrected activation energy barrier for the paddle model is ≈75 kBT, and the corresponding activation time is 1028 ms or 1017 years. The conclusions of the article remain unchanged. The corrected figure and its legend appear below.
Fig. 3.
Total electrostatic solvation energy of the S4 segment and gating charge movement for lipid-exposed (a), translation (b), and rotation (c) models. (Left) Plots of the solvation energy. (Right) Plots of the total gating charge along the reaction pathway. The dashed curve represents the effect of the S3b helix on the lipid-exposed model. The solvation energy profile for the rotation model is rugged because of the complicated interfacial geometry.