Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Av. Bernardo O'Higgins 3363, Santiago, Chile.
Chem Phys Lipids. 2012 Sep;165(6):656-61. doi: 10.1016/j.chemphyslip.2012.07.001. Epub 2012 Jul 13.
The decomposition of hydrogen peroxide catalyzed by catalase entrapped in the pool of dipalmitoylphosphatidyl choline unilamellar liposomes has been studied. The rate of the process was evaluated by following the production of oxygen as a function of time. Under the experimental conditions employed the rate of oxygen production was controlled by the diffusion of hydrogen peroxide, allowing for the estimation of the diffusion coefficient of hydrogen peroxide across the liposome bilayer. The rate of diffusion across the bilayer increases with the temperature and the presence of fluidizers (n-nonanol), according with changes in the bilayer fluidity, as sensed by 1,6-diphenyl hexatriene (DPH) fluorescence anisotropy. A peculiar aspect of the data is the fast hydrogen peroxide diffusion observed at the bilayer phase transition temperature. This fast diffusion is associated to rafts fluctuations that take place in the partially melted bilayer. These fluctuations have no effect on the microviscosity sensed by DPH.
已研究过过氧化氢在被包埋于二棕榈酰磷脂酰胆碱单层囊泡池中的过氧化氢酶作用下的分解。通过随时间的变化来跟踪氧气的产生，从而评估该过程的速率。在采用的实验条件下，氧气的产生速率受过氧化氢的扩散控制，从而可以估计过氧化氢穿过脂质体双层的扩散系数。扩散穿过双层的速率随温度和流动化剂（正壬醇）的存在而增加，这与通过 1,6-二苯基己三烯（DPH）荧光各向异性感知到的双层流动性变化一致。数据的一个特殊方面是在双层相变温度下观察到的过氧化氢的快速扩散。这种快速扩散与部分熔融双层中筏子的波动有关。这些波动对 DPH 感知到的微粘度没有影响。
