File:0903 1 1.jpg

Graphical representation of a lipid bilayer (shown as a grey surface) with cholesterol molecules (shown as a green surface) embedded into the bilayer and the enzyme cholesterol oxidase (represented as a magenta colored ribbon) docked onto the membrane. One molecule of cholesterol has been docked into the active site of the enzyme. The coordinates for the bilayer were obtained by a molecular dynamics simulation (see Heller, H., Schaefer, M. & Schulten, K. "Molecular dynamics simulation of a bilayer of 200 lipids in the gel and in the liquid-crystal phases", J. Phys. Chem. (1993) 97, 8343-60). The loops that close off the active site of cholesterol oxidase (Protein Data Bank code 1MXT) and are proposed to interact with the lipid bilayer were reoriented to open the active site to the membrane. The FAD cofactor bound to cholesterol oxidase is depicted in a ball-and-stick representation. The image was made by Alice Vrielink and Artem Lyubimov using the program PYMOL (http://pymol.sourceforge.net/).