Number 184 (Story #3), June 21, 1994 by Phillip F. Schewe and Ben Stein MYOGLOBIN MYSTERIES MADE MANIFEST . Myoglobin is a red protein that stores oxygen molecules in muscle tissue. To learn more about how myoglobin works, researchers study how the protein binds to the experimentally more convenient molecule carbon monoxide (CO). In what may be one of science's coolest movies, Joel Berendzen of Los Alamos (505-665-2552) and his colleagues at the Max Planck Institute in Heidelberg, Rice University, and Brookhaven have produced the first-ever sequence showing the intrepid protein before, while, and after it reacts with CO. The researchers combined very low temperatures (to slow things down) with x-ray diffraction techniques to obtain pictures of the CO-protein pair at atomic (1.5 Angstroms) resolution. These pictures reveal that the iron atom in myoglobin moves out of the plane of the heme (the "business end" of the protein where the reaction takes place) and that bonds more distant from the CO molecule assume a high-energy state when the CO gets zapped off. (Paper at upcoming meeting of the American Crystallographic Association in Atlanta, June 27-July 1.)