The role of structure, energy landscape, dynamics, and allostery in the enzymatic function of myoglobin

The grail of protein science is the connection between structure and functi on. For myoglobin (Mb) this goal is close. Described as only a passive diox ygen storage protein in texts, we argue here that Mb is actually an alloste ric enzyme that can catalyze reactions among small molecules. Studies of th e structural, spectroscopic, and kinetic properties of Mb lead to a model t hat relates structure, energy landscape, dynamics, and function. Mb functio ns as a miniature chemical reactor, concentrating and orienting diatomic mo lecules such as NO, CO, O-2, and H2O2 in highly conserved internal cavities . Reactions can be controlled because Mb exists in distinct taxonomic subst ates with different catalytic properties and connectivities of internal cav ities.