Figure 1.

Insertion free energy and membrane interaction of Ras. (A) Potential of mean force (PMF) for the insertion of wild-type and mutant H-ras anchors into a DMPC bilayer. The computed PMF is plotted against the average distance of backbone C and O atoms’ center-of-geometry from the bilayer center (r). (B) Evolution of anchor−DMPC nonpolar contacts. Contacts are defined as the number of selected Ras heavy atoms within 4 Å of DMPC tail carbon atoms. Contacts by Ras lipid tail (heavy lines), Met182 side chain (medium thick lines), and Lys side chain (thin lines) are shown.