ミセル表面におけるレシチンとPhospholipase Dの界面反応

抄録

Hydrolysis of lecithin by phospholipase D at the mixed micelle surfaces composed of L-α-dipalmitoyl (DPPC) or dimyristoyl phosphatidylcholine (DMPC) and heptaethyleneglycol dodecylether (C₁₂-E₇) was investigated. The interfacial reaction was analyzed by measuring the fluorescence change of 8-anilino-1-naphthalenesulfate (ANS) present in the micelle solution. As the result, it was observed that, with increasing initial mol fraction of lecithin, X^O_PC, the rate constant of the enzymatic process decreased, and that an initial slow reaction occured in the mixed micelle solution with large initial mol fraction of lecithin. The rate constant decreased at higher temperature than cloud points of the mixed micelles. On the basis of these results, the interaction between phospholipase D and mixed micelles at the interface and difference of the reactivity due to the variation of the state of lecithin were discussed.