Uematsu Kohei, Yamasaki Misato, Hibi Takao, Katano Hajime
Faculty of Biotechnology, Fukui Prefectural University, Eiheiji, Fukui, Japan.
Anal Sci. 2012;28(7):657-60. doi: 10.2116/analsci.28.657.
An enzymatic reaction rate of glucose oxidase (GOD) using ferricyanide ion (Fe(CN)(6)) as an oxidant significantly increased by the addition of ε-poly-L-lysine (ε-PL). The bimolecular rate constant between GOD and Fe(CN)(6) in the presence of ε-PL reached about 10000-fold relative to what it was measured without the ε-PL, and the Michaelis constant decreased. The reaction rate reached a maximum at around pH 6, where ε-PL and GOD possess highly positive and negative charges, respectively. The increment of the reaction rate by ε-PL can be attributed to the electrostatic association of the polycationic ε-PL with the negatively charged GOD to form a polyion complex soluble in the aqueous medium. The adduction of the cationic polymer may relieve the electrostatic repulsion between GOD and Fe(CN)(6), so that the electron transfer effectively occurs between them.
通过添加ε-聚-L-赖氨酸（ε-PL），以铁氰化物离子（[Fe(CN)₆]³⁻）作为氧化剂时葡萄糖氧化酶（GOD）的酶促反应速率显著增加。在存在ε-PL的情况下，GOD与[Fe(CN)₆]³⁻之间的双分子速率常数相对于未添加ε-PL时所测得的值达到约10000倍，且米氏常数降低。反应速率在pH约为6时达到最大值，此时ε-PL和GOD分别带有高度正电荷和负电荷。ε-PL使反应速率增加可归因于聚阳离子ε-PL与带负电荷的GOD发生静电缔合，形成可溶于水介质的聚离子复合物。阳离子聚合物的加入可能减轻了GOD与[Fe(CN)₆]³⁻之间的静电排斥，从而使它们之间有效地发生电子转移。
