Myoglobin Transport of Fatty Acid in the Cell

Orthodox biochemistry and physiology proclaim that myoglobin (Mb) serves as an O2 reservoir and as a facilitated O2 transporter in the cell. Despite tomes of reports in the literature, in vivo experiments have yet to substantiate these hypothesized cellular functions. The amount of Mb in terrestrial mammals can only sustain normal physiological function for seconds, and the translational diffusion of cellular Mb appears too slow to compete significantly with free O2. New perspectives have emerged to suggest a broadened role for Mb. Indeed, recent studies have identified Mb as a fatty acid binding protein capable of augmenting fatty acid metabolism, which stands central to cardiac function. The chapter will describe and explain the experimental and molecular modeling evidence that supports the fatty acid binding property. Moreover, it will detail the diffusion modeling supporting the notion that under certain circumstances, Mb can significantly contribute as an intracellular fatty acid transporter.