Correction for Friddle et al., Interpreting the widespread nonlinear force spectra of intermolecular bonds

BIOPHYSICS AND COMPUTATIONAL BIOLOGY, APPLIED PHYSICAL SCIENCES Correction for “Interpreting the widespread nonlinear force spectra of intermolecular bonds,” by Raymond W. Friddle, Aleksandr Noy, and James J. De Yoreo, which appeared in issue 34, August 21, 2012, of Proc Natl Acad Sci USA (109:13573–13578; first published August 6, 2012; 10.1073/pnas.1202946109).

The authors note that on page 13576, right column, first paragraph, line 8 “(38 pN/nm)” should instead appear as “(27 pN/nm)”. The authors also note that Fig. 3 appeared incorrectly. The corrected figure and its legend appear below.

Fig. 3.

Model fits to the nonlinear force spectra of intermolecular bonds. (A) Force spectrum of the Ni-NTA/His6 bond measured in this work along with the data of Verbelen et al. (34). Measurements made without Ni²⁺ demonstrate the specificity of the interaction (open circles). Solid lines represent fits to Eq. 6 using identical parameters for both data sets except for the respective spring constants. (B) Force spectra of 10 data sets taken from the literature are fit to Eq. 9 assuming a generic equilibrium force and apparent transition state distance. Data are exploded along the loading rate axis for clarity. Inset: The same force spectra in their raw form illustrating the theoretical range of equilibrium force and cross-over loading rate span (shaded regions). The upward inflection at high forces in the Biotin/Avidin data of ref. 2 may be due to limited sampling rate effects (41) and enhanced force error at very fast loading rates (42). (C) The same data in B plotted in the natural coordinates of Eq. 9 (see Eq. S3) show that all spectra collapse onto a single line. (D) Biotin-avidin bond rupture data of Teulon et al. (35) are globally fitted to Eq. 9 assuming N = 1, 2, and 3 parallel bonds. Only f_eq is independently fit, while x_t and are shared. Fitted values are x_t = 0.78 Å, , and f_eq = 24.6 pN (N = 1), 58.5 pN (N = 2), 142.3 pN (N = 3). Legend in (B) refers to references and corresponding bonds as follows: Biotin/Avidin (2); LFA-1/ICAM-1 [rest 3A9] (10); Aβ-40/Aβ-40 (11); N,C,N-pincer/pyridine (12); Si₃N₄/Mica in Ethanol (14); peptide/steel (43); Integrin/Fibronectin (44; Lysozyme/Anti-Lysozyme (45); Dig/Anti-Dig (46); Actomyosin/ADP (47).