Comparison of catalytic electrochemistry of glucose oxidase between covalently modified and freely diffusing phenothiazine-labeled poly(ethylene oxide) mediator systems
Comparison of catalytic electrochemistry of glucose oxidase between covalently modified and freely diffusing phenothiazine-labeled poly(ethylene oxide) mediator systems
复制标题
共价修饰和自由扩散吩噻嗪标记聚环氧乙烷介体系统之间葡萄糖氧化酶催化电化学的比较
DOI：
10.1021/jp034189n
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发表时间：
2003
影响因子：
3.3
通讯作者：
M. Watanabe
中科院分区：
文献类型：
--
作者：
S. Imabayashi;Kazumichi Ban;T. Ueki;M. Watanabe
在底物饱和和扩散限制条件下，比较了葡萄糖氧化酶（GOx）与吩噻嗪标记的聚环氧乙烷（PT-PEO）的混合物和GOx-（PT-PEO）与酶表面赖氨酸残基共价键合的混合物的酶催化反应。虽然在两个体系中催化电流（icat）都随着[PT-PEO]/[GOx]的增加而增加，但icat对PT-PEO分子量的依赖性完全不同。在混合体系中，随着PT-PEO分子量的增加，分子间电子转移速率（ET）和PT-PEO的扩散系数（D）降低，分子间电子转移速率（ET）也随之降低。另一方面，在杂交体中，icat在分子量为3000（PT-PEO 3000）处显示出最大值，这源于从FADH 2/FADH到PT+的分子内ET速率对PT-PEO的分子量的依赖性。较大的ET率足以弥补s...
The enzyme catalytic reaction is electrochemically compared under a substrate-saturated and diffusion-limited condition between native glucose oxidase (GOx) mixed with phenothiazine-labeled poly(ethylene oxide) (PT-PEO) and GOx-(PT-PEO) hybrid with PT-PEO covalently bonded to lysine residues on the enzyme surface. Although the catalytic current (icat) increases with the ratio of [PT-PEO]/[GOx] in both systems, the dependence of the icat on the molecular weight of PT-PEO is totally different. In the mixed systems, the icat decreases with increasing the molecular weight of PT-PEO, which reflects the decreases in the diffusion coefficient (D) of PT-PEO and the intermolecular electron transfer (ET) rate from FADH2/FADH to PT+-PEO. In the hybrids, on the other hand, the icat reveals a maximum at the molecular weight of 3000 (PT-PEO3000), which originates from the dependence of the intramolecular ET rate from FADH2/FADH to PT+ on the molecular weight of PT-PEO. The greater ET rate is enough to make up for the s...