Covalent immobilisation of invertase onto a reactive film composed of 2-hydroxyethyl methacrylate and glycidyl methacrylate:: properties and application in a continuous flow system
Covalent immobilisation of invertase onto a reactive film composed of 2-hydroxyethyl methacrylate and glycidyl methacrylate:: properties and application in a continuous flow system
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DOI：
10.1016/s1369-703x(02)00170-5
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发表时间：
2003-05-01
影响因子：
3.9
通讯作者：
Arica, MY
中科院分区：
文献类型：
--
作者：
Bayramoglu, G;Akgöl, S;Arica, MY
将转化酶共价固定在聚（甲基丙烯酸羟乙酯-共-甲基丙烯酸缩水甘油酯）（聚（HEMA-GMA））膜上。的转化酶固定化能力的膜增加的GMA比例增加的膜结构。在聚（HEMA-GMA-3）组合物上固定的转化酶表现出32.7U cm（-2）膜的活性。固定化转化酶的最适温度增加了5 ℃，游离酶和固定化酶的最适pH值确定为5.0。固定化转化酶的保留活性在53%和85%之间。动力学参数进行了测定固定化转化酶以及游离酶。转化酶的迈克尔常数Km值显著大于蔗糖酶，约为0.001。2.7固定化后的V-max降低了10倍，表明酶对其底物的亲和力降低，而固定化转化酶的V-max较小。固定化转化酶的活性相对于游离转化酶是相当稳定的。反应168 h后，固定化转化酶活性仅损失8%。在35 ℃下，用200 mM蔗糖固定的转化酶的操作失活速率常数（k（opi））为8.23 × 10（-6）min（-1）。(C)2002 Elsevier Science B. V.保留所有权利。
Invertase was covalently immobilised on the poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) (poly(HEMA-GMA)) film. The invertase immobilisation capacity of the films was increased as the GMA ratio increased in the film structure. The immobilised invertase on the poly(HEMA-GMA-3) composition exhibited an activity of 32.7 U cm(-2) film. The optimum temperature of the immobilised invertase increased by 5 degreesC, and the optimal pH values for the free and the immobilised enzymes were determined as 5.0. The retained activity of the immobilised invertase was between 53 and 85%. Kinetic parameters were determined for immobilised invertase as well as for the free enzyme. The values of the Michael's constant K-m of invertase were significantly larger, ca. 2.7 times upon immobilisation, indicating decreased affinity by the enzyme for its substrate, whereas V-max was smaller for immobilised invertase. Activity of the immobilised invertase was quite stable with respect to free counterpart. After 168 h reaction, only 8% of immobilised invertase activity was lost. The operational inactivation rate constant (k(opi)) of the immobilised invertase at 35 degreesC with 200 mM sucrose was 8.23 x 10(-6) min(-1). (C) 2002 Elsevier Science B.V. All rights reserved.