Myoglobin and Mitochondria: How Does The “Oxygen Store” Work?

The most important condition for functioning of all living aerobic organisms is continuous supply of sufficient oxygen. The access of oxygen to metabolic processes in cells is mediated by the respiratory proteins, tetrameric blood hemoglobin (Hb) and monomeric muscle myoglobin (Mb). Myoglobin is expressed in red muscles in response to mitochondrial demand for oxygen, transporting it from sarcolemma to mitochondria [1-3]. Particularly high Mb concentration is observed in muscles of aquatic mammals, who spend a long time underwater for food, and also in those of highland animals, living under deficient O2, which served as the basis for the hypothesis that myoglobin is the “oxygen store” for mitochondrial cytochrome c oxidase.