Figure 3.

Binding of the drug lisinopril in the catalytic pocket of angiotensin-converting enzyme. Students visualize the enzyme-drug interaction and the importance of the imbedded zinc ion (cofactor in the enzyme). Zinc is held in the enzyme by two histidine residues and a glutamate residue. The Zinc ion also makes contact with the drug lisinopril via its corboxylate moeity. Dotted lines represent the complex hydrogen bonding network between protein and the drug. The figure was created using PyMol software.