Figure 6.

Curvature. (A) An atom of protein A centered in a has common facets with two atoms of protein B centered in b₁ and b₂, and these facets share an edge, ɛ. The three atoms form a Delaunay triangle (heavy line). The discrete curvature at edge ɛ is the product of the length of the edge by the dihedral angle β, which is equal to the angle in a of the Delaunay triangle. (B) Distribution of the values of |β| in the 1udi interface. The peak near 15° represents triangles where the atoms centered in b₁ and b₂ are covalently linked. (C) The kallikrein–pancreatic trypsin inhibitor (2kai) interface, which has the largest mean curvature s_H = 17° in our sample, is concave toward the inhibitor drawn as a ribbon. The concavity is particularly marked around Lys 15 (drawn in van der Waals spheres), which occupies a well-defined pocket on the protease surface.