[Changes in external membrane lipids of the mouse liver mitochondria and kinetic parameters of membrane-bound monoaminoxidase in vivo and in vitro].
Influence of lipids on monoamine oxidase (MAO) activity in external mitochondrial membranes of mice liver cells was studied. Content of acidic phospholipids (phosphatidyl serine + phosphatidyl inositol) correlated with Km value of tyramine deamination. The data obtained suggest that these phospholipids are important for the surface membrane charge which determines MAO affinity to the substrate. Relationship was also found between the viscosity of lipid components and Km, Vmax and the rate of inhibition by an excess of the substrate. Thus, the structural state of membrane lipid components affects the MAO affinity to the substrate, catalytic activity of the enzyme and its sensitivity to regulatory effectors. Among the kinetic patterns maximal rate, i.e. catalytic activity of the enzyme, was distinctly dependent on the viscosity of lipid bilayer.
D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000201:enzymology / Q000378:metabolism*; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D051379:Mice; D008930:Mitochondria, Liver / Q000201:enzymology*; D008995:Monoamine Oxidase / Q000378:metabolism*; D010847:Picolines / Q000494:pharmacology; D011837:Radiation-Protective Agents / Q000494:pharmacology; D014783:Viscosity
D008051:Lipid Bilayers; D008054:Lipid Peroxides; D008563:Membrane Lipids; D010847:Picolines; D011837:Radiation-Protective Agents; D008995:Monoamine Oxidase; C009820:6-methyl-2-ethyl-3-hydroxypyridine
Modifikatsiia lipidov naruzhnoĭ membrany mitokhondriĭ pecheni mysheĭ i kineticheskikh parametrov membranosviazannoĭ monoaminoksidazy in vivo i in vitro.