title: Myoglobin and hemoglobin rotational diffusion in the cell.
abstract: The detection of the 1H NMR signal of myoglobin (Mb) in tissue opens an opportunity to examine its cellular diffusion property, which is central to its purported role in facilitating oxygen transport. In perfused myocardium the field-dependent transverse relaxation analysis of the deoxy Mb proximal histidyl NdeltaH indicates that the Mb rotational correlation time in the cell is only approximately 1.4 times longer than it is in solution. Such a mobility is consistent with the theory that Mb facilitates oxygen diffusion from the sarcoplasm to the mitochondria. The microviscosities of the erythrocyte and myocyte environment are different. The hemoglobin (Hb) rotational correlation time is 2.2 longer in the cell than in solution. Because both the overlapping Hb and Mb signals are visible in vivo, a relaxation-based NMR strategy has been developed to discriminate between them.
authors.affiliation: Biological Chemistry Department, University of California Davis, 95616-8635, USA.
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.forename: U
authors.initials: U
authors.lastname: Kreutzer
authors.forename: Y
authors.initials: Y
authors.lastname: Chung
authors.forename: T
authors.initials: T
authors.lastname: Jue
mesh_terms: D000818:Animals; D004058:Diffusion; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D006454:Hemoglobins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D006639:Histidine / Q000737:chemistry / Q000378:metabolism; D006736:Horses; D006801:Humans; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D009211:Myoglobin / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010100:Oxygen / Q000378:metabolism; D014783:Viscosity
chemical_list: D006454:Hemoglobins; D009211:Myoglobin; D006639:Histidine; C100003:deoxyhemoglobin; D010100:Oxygen