THE STUDY OF DYNAMIC MICROSTRUCTURE OF MITOCHONDRIAL OUTER AND INNER MEMBRANES PHOSPHOLIPID FROM RAT MYOCARDIUM
大鼠心肌线粒体内、外膜磷脂动态结构的研究

The viscosity of the phospholipid bilayer and the wobbling angle of the phospholipid molecules of outer and inner membranes from rat cardiac mitochondria were measured with a nanosecond time-resolved fluorometer using a fluorophore, 1,6 - diphenyl - 1,3,5 -hexatriene (DPH). Measurements were also made on liposomes prepared by lipids extracted from each membrane. Phospholipid constituents in membranes were analysed by HPLC. Results showed that membrane viscosity and wobbling angle of phospholipids of outer membrane fluidity of mitochondria mainly reflected the motion state of outer mitochondrial membrane. The inner membranes showed a high or viscosity and lower rotational diffussion constant of phospholipids as compared with outer membranes. The liposomes prepared from lipid extracts of outer and inner membranes showed a lower viscosity and/or higher wobbling angle of phospholipids as compared with the membranes themselves. These results suggest that the limitation of molecular motion of phospholipids by membrane proteins results in an increase in the average viscosity and the microdynamic values obtained in the inner membrane fraction reflect the interacion between phospholipid and protein which is abundant in the inner membrane.