Interaction of fatty acid with myoglobin

Abstract Upon titration with palmitate, the 1 H NMR spectra of metmyoglobin cyanide (MbCN) reveal a selective perturbation of the 8 heme methyl, consistent with a specific interaction of myoglobin (Mb) with fatty acid. Other detectable hyperfine shifted resonances of the heme group remain unchanged. Mb also enhances fatty acid solubility, as reflected in a more intense methylene peak of palmitate in Mb solution than in Tris buffer. Ligand binding analysis indicates an apparent palmitate dissociation constant ( K d ) of 43 μM. These results suggest that Mb can bind fatty acid and may have a role in facilitating fatty acid transport in the cell.