Redox properties and Moessbauer spectroscopy of Azotobacter vinelandii bacterioferritin
Redox properties and Moessbauer spectroscopy of Azotobacter vinelandii bacterioferritin
复制标题
维氏固氮菌细菌铁蛋白的氧化还原特性和穆斯堡尔谱
DOI：
10.1021/bi00363a023
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发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
E. Stiefel
中科院分区：
文献类型：
--
作者：
G. Watt;R. Frankel;G. Papaefthymiou;K. Spartalian;E. Stiefel
本文报道了亚硝唑杆菌中铁蛋白的生化表征、氧化还原测定和穆斯堡尔光谱数据。从培养20和40 h的细菌细胞中获得了600 ~ 2400个Fe原子/分子的铁蛋白样品，细菌铁蛋白平均含有1.4 Fe/Pi和0.5 b型血红素/亚基。血红素还原电位为-475 mV，铁核还原电位为-420 mV，后者与ph值无关。单杆菌铁蛋白（只含血红素）的还原电位为-225 mV，比有铁核的还原电位高250 mV。氧化和部分还原细菌铁蛋白的穆斯堡尔光谱清晰地显示出Fe3+和Fez+的离散，前者呈反铁磁耦合结构。细菌铁蛋白的阻滞温度低于哺乳动物铁蛋白。细菌铁蛋白中Fe2+的参数与哺乳动物铁蛋白中的相似。
Biochemical characterization, redox measurements, and Mossbauer spectral data of reduced and oxidized bacterial ferritin from Azotobacter vinelandii are reported. Ferritin samples ranging from 600 to 2400 Fe atoms/molecule were obtained from bacterial cells grown 20 and 40 h. The bacterial ferritin contained an average of 1.4 Fe/Pi and 0.5 b-type heme/subunit. Reduction potentials of -475 mV for heme reduction and -420 mV for core iron reduction were determined, the latter value being apparently independent of pH. Apobacterioferritin (containing only heme) has a reduction potential of -225 mV, a value 250 mV more positive than when the core is present. Mossbauer spectra of oxidized and partially reduced bacterial ferritin clearly show discrete Fe3+ and Fez+, the former in an antiferromagnetically coupled structure. Blocking temperatures are lower for bacterial ferritin than for mammalian ferritin. The parameters for Fe2+ in bacterial ferritin are similar to those in reduced mammalian ferritin.