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The effect of structure of the enzyme-fixed polymers on the reactivity of enzyme

酶固定聚合物的结构对酶反应活性的影响

基本信息

批准号：
01550721
负责人：
NAKAGAWA Tsutomu
金额：
$ 1.22万
依托单位：
Meiji University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

Immobilized enzymes are considered to be a kind of modified enzymes and used in the fields of bioreactors and sensors. The reactivity of enzymes which is not in the form of their homogeneous solutions was observed by Nelson and Griffins. There have been lots of papers concerning modified enzymes, especially sensors. The objective of this study is to clarify the effect of polymers which have copper in membranes on the reactivity of immobilized ascorbic acid oxidlse (ASOD), because ASOD is a special enzyme containing copper and the relationships between the function and the membrane potential. The sensor which has ASOD in the membrane are now used in order to know the concentration of ascorbic acid in raw fishes or Vitamin C.At first, poly (vinyl chloride) having N-methyl-N-carboxymethyl dithiocarbamate which is able to form a chelate complex, was prepared and used as a polymer for combining ASOD. A thin membrane was casted from the solution to which ASOD was added. Then copper was impre … More gnated into the membrane. Oxygen electrode system was combined with membranes prepared. A current reduction was measured by oxygen electrode. The relationships between the concentration of L-ascorbic acid and the decrease of the electric current, were obtained. However, the current reduction of the copper-containing chelate polymer, was not so high as that of non-chelate polymer. It is considered that crosslinking in the membrane caused the decrease of the swelling and reduced oxygen diffusivity. In stead, using salt-forming polymers such as copoly (methyl methacrylate-acrilic acid) gave the higher decrease of the electric current. This phenomena suggest that both hydration of the membrane and the presence of copper enhanced the response of the sensor.Thin membranes of Chloromethylated polymay-gamma-methyl-L-glutamate were prepared on the surface of a porous polypropyrene sheet by the spin-caseted method and quariernized with trimthylamine. ASOD was fixed by the identical way. This type of the sensor was found to be excellent in both sensitivity and durability.Also, the relationships between response of the enzyme-fixed composite membranes and their change of the membrane potential was obtained and analyzed with our new membrane potential theory. Less

固定化酶被认为是一种修饰酶，广泛应用于生物反应器和传感器等领域。Nelson和Griffins观察到酶的反应性不是以其均相溶液的形式存在的。关于修饰酶，特别是传感器，已经有了大量的论文。本研究的目的是阐明膜中含铜的聚合物对固定化抗坏血酸氧化酶(ASOD)反应活性的影响，因为ASOD是一种特殊的含铜酶，以及其功能与膜电位的关系。膜上有ASOD的传感器现在被用来知道生鱼或维生素C中抗坏血酸的浓度。首先，制备了含有N-甲基-N-羧甲基二硫代氨基甲酸酯的聚氯乙烯，并将其作为聚合物与ASOD结合。从加入ASOD的溶液中浇铸出一层薄膜。然后铜是印象深刻的…更多的虫子进入细胞膜。将氧电极体系与制得的膜结合起来。用氧电极法测定了电流的减少量。得到了L抗坏血酸的浓度与电流下降的关系。然而，含铜螯合聚合物的电流还原没有非螯合聚合物高。认为膜中的交联剂降低了膜的溶胀度，降低了氧的扩散系数。相反，使用成盐聚合物，如共聚(甲基丙烯酸甲酯-丙烯酸甲酯)，电流下降较大。这一现象表明膜的水化和铜的存在都增强了传感器的响应。采用旋转层法制备了氯甲基化的聚γ-甲基-L-谷氨酸甲酯薄膜，并用三甲胺对其进行了表面处理。用相同的方法固定ASOD。该传感器具有良好的灵敏度和耐用性，并利用新的膜电位理论分析了酶固定复合膜的响应与膜电位变化之间的关系。较少