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Stabilization and Activation of Enzymes by Adsorptive Immobilization with Water-Soluble Polymers and Its Application to Enzyme Membrane Reactor

水溶性聚合物吸附固定化酶的稳定和活化及其在酶膜反应器中的应用

基本信息

批准号：
04555229
负责人：
TERAMOTO Masaaki
金额：
$ 3.26万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

1. Stabilization of enzymes and accelerating effect of water-soluble polymers on enzymic reaction(1) By addition of water-soluble cationic polymers such as polyethyleneimine(PEI) and DEAE-dextran, thermal stability of glucose dehydrogenase (GDH) was remarkably increased. It was deduced that adsorption of polymers to GDH prevents unfolding of GDH by multi-point binding.(2) The rate of GDH-catalyzed reaction was enhanced by addition of PEI at low coenzyme(NAD()^+) concentration. The results of kinetic study suggested that the accelerating effect is due to PEI-mediated enrichment of coenzyme NAD(P)^+ near GDH interacting with PEI.(3) In the reduction of phenylpyruvic acid(PhP) by lactate degydrogenase(LDH)/GDH conjugate system, addition of PEI was very effective for increasing reaction rate.(4) The apparent equilibrium constant of alcohol dehydrogenase(ADH)-catalyzed reaction was increased by addition of PEI, resulting in improvement of the conversion of PhP in LDH/ADH-catalyzed reaction.2. Effect of water-soluble polymers on performance of enzyme membrane reactorIn the continuous reduction of PhP by the LDH/GDH conjugate enzyme system using a continuoustype hollow fiber enzyme reactor, addition of PEI was effective for increasing the conversion of PhP.3. Preparation of microporous charged membrane by plasma-graft polymerization for membrane enzyme reactor.Microporpus charged membranes were prepared by grafting acrylic acid to microporous polyethylene membranes, and the effect of preparation condition of the membrane properties was studied. Membranes with high charge density were successfully prepared.

1. 酶的稳定及水溶性聚合物对酶反应的加速作用(1)聚乙烯亚胺（PEI）、deae -葡聚糖等水溶性阳离子聚合物的加入，显著提高了葡萄糖脱氢酶（GDH）的热稳定性。推断聚合物对GDH的吸附阻止了GDH通过多点结合展开。(2)在低辅酶（NAD()^+）浓度下加入PEI可提高gdh催化反应的速率。动力学研究结果表明，加速效应是由于PEI介导的辅酶NAD(P)^+在GDH附近富集与PEI相互作用所致。(3)乳酸脱氢酶(LDH)/GDH偶联体系还原苯基丙酮酸（PhP）时，PEI的加入对提高反应速率非常有效。(4) PEI的加入提高了醇脱氢酶（ADH）催化反应的表观平衡常数，从而提高了LDH/ADH催化反应中PhP的转化率。水溶性聚合物对酶膜反应器性能的影响在连续型中空纤维酶反应器中，LDH/GDH偶联酶体系连续还原PhP时，PEI的加入可有效提高PhP.3的转化率。膜酶反应器用等离子体接枝聚合法制备微孔带电膜。将丙烯酸接枝到微孔聚乙烯膜上制备了微porpors带电膜，并研究了制备条件对膜性能的影响。成功制备了高电荷密度的膜。