title: [Optimizing synthesis of conjugates of superoxide dismutase and catalase with aldehyde dextrans in surfactant microemulsions in heptane].
abstract: Stable microemulsions in heptane retaining considerable amounts of the polar phase were obtained by using Aerosol OT (AOT), Triton X-45, and catalase. Conjugates of superoxide dismutase (SOD) and catalase with aldehyde dextrans (AD) were synthesized in surfactant microemulsions in heptane. Effects of the reaction duration, the microemulsion polar phase volume, and concentrations of enzymes and modifiers on the properties of these conjugates were studied. The catalytic properties of conjugates depended on the nature of the surfactants used to stabilize the microemulsions, the initial concentration of protein in the reaction mixture, and the enzyme: modifier ratio. The degree of modification of the enzymes and the stabilities of their conjugates during isolation from microemulsions by a water-acetone solution depended on the concentration of the AD used. The catalytic properties of the conjugates synthesized were compared, and their stabilities in the presence of H2O2 were described. We suggested a simple method of transformation of whole kinetic curves of H2O2 conversion in coordinates 1/ln([H2O2]0/[H2O2]t - 1/t for simultaneous measurement of the constant of the catalase inactivation rate by H2O2 (Cin, S-1) and the rate constant of the catalase complex 1 interaction with the second H2O2 molecule (C2, M-1 S-1). This method was tested experimentally. Values C2 and Cin for catalase and its conjugates with ADs were compared, and these results were discussed.
authors.forename: A N
authors.initials: AN
authors.lastname: Eremin
authors.forename: D I
authors.initials: DI
authors.lastname: Metelitsa
mesh_terms: D002374:Catalase / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D003911:Dextrans / Q000737:chemistry*; D004655:Emulsions; D006536:Heptanes / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D003911:Dextrans; D004655:Emulsions; D006536:Heptanes; D013501:Surface-Active Agents; D002374:Catalase; D013482:Superoxide Dismutase