A study of cytochrome bo3 in a tethered bilayer lipid membrane.
A study of cytochrome bo3 in a tethered bilayer lipid membrane.
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DOI：
10.1016/j.bbabio.2010.01.012
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发表时间：
2010-12
影响因子：
4.3
通讯作者：
Jeuken, Lars J. C.
中科院分区：
文献类型：
--
作者：
Weiss, Sophie A.;Bushby, Richard J.;Evans, Stephen D.;Jeuken, Lars J. C.
关键词：
已经开发了一种测定法，其中来自大肠杆菌的泛醇氧化酶，细胞色素bo 3（cbo 3）的活性被确定为系留脂质双层膜（tBLMs）中疏水底物泛醇-10（UQ-10）的函数。原位加入UQ-10，同时通过循环伏安法测定酶活性和膜中UQ-10的浓度。UQ-10在高于5-10 pmol/cm 2的浓度下抑制Cbo 3，而不存在产物抑制。循环伏安法也被用于验证三种抑制剂的作用;氰化物，抑制氧还原; 2-正庚基-4-羟基喹啉N-氧化物（HQNO），抑制醌氧化和Zn（II），认为其阻断氧还原和质子泵活性所需的质子通道。用HQNO和Zn（II）抑制的cbo 3的电化学行为几乎相同，表明Zn（II）离子抑制由醌醇引起的酶还原，而不是氧还原。这表明，在Zn（II）浓度低于50 μM时，cbo 3的质子释放受到抑制，但不抑制将氧还原为水所需的质子吸收。
An assay has been developed in which the activity of an ubiquinol oxidase from Escherichia coli, cytochrome bo3 (cbo3), is determined as a function of the hydrophobic substrate ubiquinol-10 (UQ-10) in tethered lipid bilayers membranes (tBLMs). UQ-10 was added in situ, while the enzyme activity and the UQ-10 concentration in the membrane have been determined by cyclic voltammetry. Cbo3 is inhibited by UQ-10 at concentrations above 5-10 pmol/cm2, while product inhibition is absent. Cyclic voltammetry has also been used to characterise the effects of three inhibitors; Cyanide, inhibiting oxygen reduction; 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO), inhibiting the quinone oxidation and Zn(II), thought to block the proton channels required for oxygen reduction and proton pumping activity. The electrochemical behaviour of cbo3 inhibited with HQNO and Zn(II) is almost identical, suggesting that Zn(II) ions inhibit the enzyme reduction by quinol, rather than oxygen reduction. This suggests that at Zn(II) concentration below 50 μM the proton release of cbo3 is inhibited, but not the proton uptake required to reduce oxygen to water.
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影响因子：
7.4
作者：
Jeuken, Lars J. C.;Weiss, Sophie A.;Henderson, Peter J. F.;Evans, Stephen D.;Bushby, Richard J.
通讯作者：
Bushby, Richard J.
影响因子：
2.9
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
4.8
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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