FIGURE 11.

Contour maps of PIP₂ density in the membrane plane. The area per square of the grid corresponds to one lipid molecule. (The square grid is used here just for display; the simulations were carried out using a two-dimensional hexagonal lattice.) The figure on the left, a, is for a flexible 20-segment chain interacting with a fluid membrane of average composition PC:PS:PIP₂ = 98:1:1. The figure on the right, b, is for a rodlike polymer of the same length and charge. The rod is placed at distance z = 1 from the membrane. The polymer's first segment is fixed at z₁ = 1. The numbers labeling the color code indicate the local mole fractions of PIP₂. The average membrane concentration is 0.01.