Fig. 4. Space-filling models of human α-thrombin and haemadin, showing the surface potential of the two molecules. Positive charges are displayed in blue, negative charges in red, with darkest blue and red colours corresponding to electrostatic potentials beyond –10 and +10 kT/e, respectively. The plot was prepared with GRASP (Nicholls et al., 1993). The thrombin component (B) is shown in the standard orientation, while haemadin (A) is rotated along the y-axis to present the thrombin binding surface to the viewer. Some of the residues of the interacting interfaces are labelled.