Table 1.

Material property values of PCDH15

[Ca2+]b, nmlclinker, nmkfolded, mN/mΔlcA, nmΔlcB, nmΔlcC, nm
3 mM2.9 ± 0.51.4 ± 0.59 ± 44.0 ± 0.215.8 ± 0.7
20 µM3.1 ± 0.41.3 ± 0.511 ± 53.9 ± 0.415.0 ± 0.635 ± 1
  • The parameters of a polymer model (SI Appendix) were as follows: b, length of each stiff segment of the folded protein; lclinker, contour length of each flexible linker between the stiff segments; kfolded, enthalpic stiffness of the folded protein; ΔlcA, contour length increase, type A; ΔlcB, contour length increase, type B; ΔlcC, contour length increase, type C. The parameter values were determined from fits of the model to the force-extension curves in Fig. 2. The values for the folded protein are largely independent of the Ca2+ concentration. ΔlcC is in good agreement with the expected contour-length change per unfolded cadherin domain. Fitted parameter values are given as mean ± SEM for five experiments at a Ca2+ concentration of 3 mM and for eight experiments at a Ca2+ concentration of 20 µM.