Direct voltammetry and catalysis with Mycobacterium tuberculosis catalase-peroxidase, peroxidases, and catalase in lipid films.
Direct voltammetry and catalysis with Mycobacterium tuberculosis catalase-peroxidase, peroxidases, and catalase in lipid films.
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DOI：
10.1021/ac010701u
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发表时间：
2002
影响因子：
7.4
通讯作者：
Zhe Zhang;S. Chouchane;R. Magliozzo;J. Rusling
中科院分区：
文献类型：
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作者：
Zhe Zhang;S. Chouchane;R. Magliozzo;J. Rusling
二肉芽酰基磷脂酰胆碱和结核杆菌过氧化氢酶过氧化物酶（KatG）、几种过氧化物酶、肌红蛋白和过氧化氢酶的稳定膜在热解石墨电极上表现出可逆的FeIII/FeII伏安，过氧化氢和氧气的催化电流。这些膜对H2O2在0 V下的电流响应可能包含催化循环过程中产生的氧的催化还原的重要贡献。在H2O2存在下，pH为6时，基于0 V稳态电流与SCE的相对表观周转率依次为辣根过氧化物酶>细胞色素c过氧化物酶(CcP) >大豆过氧化物酶>肌红蛋白> KatG >过氧化氢酶。对于非常有效的过氧化物清除剂KatG和过氧化氢酶来说，较低的电流可能与它们的化合物I在H2O2存在下的不稳定性有关。KatG催化氧的电化学还原效率高于过氧化氢酶和CcP，但低于其他过氧化物酶。含有葡萄糖氧化酶和过氧化物酶的DMPC膜对葡萄糖具有良好的分析响应，证明了双酶-脂质膜用于生物传感器制造的可行性。
Stable films of dimyristoylphosphatidylcholine and M. tuberculosis catalase-peroxidase (KatG), several peroxidases, myoglobin, and catalase showed reversible FeIII/FeII voltammetry on pyrolytic graphite electrodes and catalytic current for hydrogen peroxide and oxygen. Amperometric responses for these films to H2O2 at 0 V are likely to contain significant contributions from catalytic reduction of oxygen produced during the catalytic cycles. Relative apparent turnover rates at pH 6 based on steady-state currents at 0 V versus SCE in the presence of H2O2 were in the order horseradish peroxidase > cytochrome c peroxidase (CcP) > soybean peroxidase > myoglobin > KatG > catalase. Lower currents for the very efficient peroxide scavengers KatG and catalase may be related to the instability of their compounds I in the presence of H2O2. KatG catalyzed the electrochemical reduction of oxygen more efficiently than catalase and CcP but less efficiently than the other peroxidases. DMPC films incorporating glucose oxidase and peroxidases gave good analytical responses to glucose, demonstrating the feasibility of dual enzyme-lipid films for biosensor fabrication.