Skjeldal L, Markley J L, Coghlan V M, Vickery L E
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison.
Biochemistry. 1991 Sep 17;30(37):9078-83. doi: 10.1021/bi00101a024.
We report the observation of paramagnetically shifted (hyperfine) proton resonances from vertebrate mitochondrial [2Fe-2S] ferredoxins. The hyperfine signals of human, bovine, and chick [2Fe-2S] ferredoxins are described and compared with those of Anabaena 7120 vegetative ferredoxin, a plant-type [2Fe-2S] ferredoxin studied previously [Skjeldal, L., Westler, W. M., & Markley, J. L. (1990) Arch. Biochem. Biophys. 278, 482-485]. The hyperfine resonances of the three vertebrate ferredoxins were very similar to one another both in the oxidized state and in the reduced state, and slow (on the NMR scale) electron self-exchange was observed in partially reduced samples. For the oxidized vertebrate ferredoxins, hyperfine signals were observed downfield of the diamagnetic envelope from +13 to +50 ppm, and the general pattern of peaks and their anti-Curie temperature dependence are similar to those observed for the oxidized plant-type ferredoxins. For the reduced vertebrate ferredoxins, hyperfine signals were observed both upfield (-2 to -18 ppm) and downfield (+15 to +45 ppm), and all were found to exhibit Curie-type temperature dependence. This pattern and temperature dependence are distinctly different from those found with reduced plant-type ferredoxins which have signal centered around +120 ppm with Curie-type temperature dependence, assigned to cysteines which interact with Fe(III), and signals centered around +20 ppm with anti-Curie temperature dependence, assigned to cysteines which interact with Fe(II) [Dugad, L. B., La Mar, G. N., Banci, L., & Bertini, I. (1990) Biochemistry 29, 2263-2271].(ABSTRACT TRUNCATED AT 250 WORDS)
我们报告了对脊椎动物线粒体[2Fe-2S]铁氧化还原蛋白顺磁位移（超精细）质子共振的观察结果。描述了人、牛和鸡[2Fe-2S]铁氧化还原蛋白的超精细信号，并将其与鱼腥藻7120营养型铁氧化还原蛋白（一种先前研究过的植物型[2Fe-2S]铁氧化还原蛋白）的信号进行了比较[Skjeldal, L., Westler, W. M., & Markley, J. L. (1990) Arch. Biochem. Biophys. 278, 482 - 485]。三种脊椎动物铁氧化还原蛋白的超精细共振在氧化态和还原态下彼此非常相似，并且在部分还原的样品中观察到了缓慢的（在核磁共振尺度上）电子自交换。对于氧化的脊椎动物铁氧化还原蛋白，在抗磁包络线的低场（从+13至+50 ppm）观察到超精细信号，峰的总体模式及其居里温度依赖性与氧化的植物型铁氧化还原蛋白所观察到的相似。对于还原的脊椎动物铁氧化还原蛋白，在高场（-2至-18 ppm）和低场（+15至+45 ppm）均观察到超精细信号，并且发现所有信号均表现出居里型温度依赖性。这种模式和温度依赖性与还原的植物型铁氧化还原蛋白明显不同，后者的信号以+120 ppm为中心且具有居里型温度依赖性，归因于与Fe(III)相互作用的半胱氨酸，以及以+20 ppm为中心且具有反居里温度依赖性的信号，归因于与Fe(II)相互作用的半胱氨酸[Dugad, L. B., La Mar, G. N., Banci, L., & Bertini, I. (1990) Biochemistry 29, 2263 - 2271]。（摘要截短于250字）
