Redox and spectral properties of flavodoxin from Anabaena 7120.
Redox and spectral properties of flavodoxin from Anabaena 7120.
复制标题
鱼腥藻 7120 中黄素氧还蛋白的氧化还原和光谱特性。
DOI：
10.1016/0003-9861(90)90519-5
复制
发表时间：
1990
影响因子：
3.9
通讯作者：
Markley,JL
中科院分区：
文献类型：
--
作者：
Paulsen,KE;Stankovich,MT;Stockman,BJ;Markley,JL
我们在这里报告了来自鱼腥藻7120的黄氧素的分光光度和电化学性质，并将这些性质与之前研究的黄氧素的性质进行了比较。摩尔吸收系数已被确定为所有三种氧化态的这种蛋白质，在不同的波长。对于氧化型黄氧还蛋白，在464和373 nm处最大吸收的摩尔吸收系数分别为9200和8500 m − 1 cm −1。第一个电子的还原产生了中性蓝半醌，其在575 nm处具有最大吸收。在575 nm处的摩尔吸收系数为200 m − 1 cm − 1（氧化形式）、5100 m − 1 cm − 1（半醌形式）和250 m − 1 cm − 1（氢醌形式）。氧化还原电位已被确定，在6.0至8.5的pH范围内，为两个电子转移。在pH 7.0时，第一次和第二次电子转移的中点电位值分别为-0.196和-0.425 V。我们确定，第一个电子转移是pH依赖性的，质子转移伴随着这一个电子转移。还确定了第二电子转移在6.0至8.5的pH范围内是pH无关的。
We report here on the spectrophotometric and electrochemical properties of the flavodoxin fromAnabaena7120 and compare these properties with those of flavodoxins that have been studied previously. Molar absorption coefficients have been determined for all three oxidation states of this protein, at various wavelengths. For oxidized flavodoxin, molar absorption coefficients for the absorption maxima at 464 and 373 nm were 9200 and 8500m−1cm−1, respectively. Reduction by the first electron produced a neutral blue semiquinone which exhibited an absorption maximum at 575 nm. The molar absorption coefficients at 575 nm were 200m−1cm−1for the oxidized form, 5100m−1cm−1for the semiquinone form, and 250m−1cm−1for the hydroquinone form. Redox potentials have been determined, in the pH range of 6.0 to 8.5, for both electron transfers. At pH 7.0, the midpoint potential values for the first and second electron transfers were −0.196 and −0.425 V, respectively. We determined that the first electron transfer is pH dependent and that a proton transfer accompanies this one electron transfer. It was also determined that the second electron transfer is pH independent in the pH range of 6.0 to 8.5.