Extended Data Figure 9. Computational modeling of hRegIIIα insertion into membranes.

a, Top down view of the numeric grid and complex boundary used in the elasticity calculations to represent the upper leaflet. The protein complex occupies the white space in the center, and the membrane-protein contact curve is the red-white boundary. The membrane is modeled in all non-white regions. The rectangular grid for the elasticity solver is shown here colored by the membrane bending energy density (red is high bending energy and blue is low bending energy). This calculation corresponds to the membrane bending shown in Fig. 3g. b-d, Numeric convergence of the model. b, Convergence of the elastostatic energy. In all panels, percent error was calculated as 100·|(E(n) − E(nmax))/E(nmax)|, where E(n) = energy calculated with n grid points, and nmax = maximum number of grid points used. The elastic energy converges smoothly as n increases, and we used n = 400 in both the x and y directions for all calculations in the main text, which gives a 5% error. c, Convergence of the electrostatic energy. Percent error of the dipole charge-protein interaction energy (diamonds), protein solvation energy (squares), anionic lipid charge-protein interaction energy (circles) and the total electrostatic energy (triangles) are shown as a function of the grid discretization. A value of n = 161 was used for the calculations discussed in the main text resulting in a total electrostatic error of 2.5%. d, Convergence of the non-polar energy. A discretization of n = 100 points was used for the calculations reported in the main text, and this has a very small error on the order of 0.1%. Values used for calculations in the main text are indicated by *. e,f, Electrostatic potential of the hRegIIIα pore complex. e, In-plane view. The Poisson-Boltzmann equation was solved using APBS after embedding the complex in a low dielectric region mimicking the lipid bilayer²³. The low dielectric membrane region is deformed corresponding with the lowest energy shape predicted by our physics-based computational model. Positive (blue) isocontours of the electrostatic potential are drawn at +5 kcal/mol/e. f, Out-of-plane view. All details are identical to those in panel a. Both positive (blue) and negative (red) isocontours of the electrostatic potential are drawn at ±5 kcal/mol/e. g, Table showing bilayer material properties used in the modeling calculations. h, Table showing model parameters.