包衣酶在油/水两相体系中催化水解橄榄油反应

Surfactant-Coated Lipase as a Catalyst for Hydrolytic Reaction of Olive Oil in Organic/Aqueous Two-Phase System

用合成的谷氨酸十二烷基酯核糖醇对来源于Candidarugosa的脂肪酶包衣后在油/水两相体系中水解橄榄油为反应模型.确定了最佳水油比范围为1～3,最适pH值为7.0左右,温度为30℃,油相有机溶剂为异辛烷.包衣酶的最大活性达到48.8mmol·min-1·g-1蛋白质,是天然酶活性的1.8倍.对底物选择性研究表明:包衣酶和天然酶的最适底物均为橄榄油,酰基链越长,酶活越高.包衣酶的米氏常数只有天然酶的一半,最大反应速度是天然酶的1.4倍.

As a model reaction hydrolytic reactions of olive oil in an organic/aqueous two-phase system was (ca-)(talyzed) by the Candida rugosa lipase coated with glutamic acid didodecyl ester ribitol. The optimum volume ratio of the aqueous to organic phases was within 1 to 3. The optimum aqueous pH and reaction temperature were around 7.0 and 30 ℃ respectively, and the best organic solvent was isooctane. The maximum activity of the surfactant-coated lipase reached 48.8 mmol·min^(-1)·g^(-1) protein, 1.8 times higher than that of the native lipase. The coated lipase displayed the similar substrate specificity to the native lipase and olive oil was found to be the most suitable substrate among the tested esters. The Michaelis-Menten kinetics showed that the Michaelis constant ( K_ m) of the coated lipase was only half that of the native lipase while the maximum velocity ( v _(max)) was 1.4 times higher.