Resonance Raman spectroscopic studies of hydroperoxo-myoglobin at cryogenic temperatures
Resonance Raman spectroscopic studies of hydroperoxo-myoglobin at cryogenic temperatures
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DOI：
10.1021/ja036949d
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发表时间：
2003-11-12
影响因子：
15
通讯作者：
Sligar, SG
中科院分区：
文献类型：
--
作者：
Ibrahim, M;Denisov, IG;Sligar, SG
根据以前的报告（Gaasyna，Z. FEBS Lett. 1979，106，213-218和Leibl，W.; Nitschke，W.; Huettermann，J. Biochim. Biophys. Acta 1986，870，20-30）在低温下氧化肌红蛋白的放射性还原样品已经通过光吸收和EPR研究显示在77 K下直接产生过氧化物结合的肌红蛋白。退火到185 K附近的温度诱导质子转移，导致氢过氧血红素衍生物的形成。退火样品的共振拉曼研究已允许，第一次，直接观察到的关键v（Fe-O）的伸缩模式的生理上重要的Fe-OOH片段的这种无处不在的中间体。用O-18（2）取代后，向较低能量移动25 cm（-1），在氘代溶剂溶液中制备的样品向较低能量移动5 cm（-1），这有力地支持了将该模式归属于出现在617 cm（-1）处的特征。
In agreement with previous reports (Gasyna, Z. FEBS Lett. 1979, 106, 213-218 and Leibl, W.; Nitschke, W.; Huettermann, J. Biochim. Biophys. Acta 1986, 870, 20-30) radiolytically reduced samples of oxygenated myoglobin at cryogenic temperatures have been shown by optical absorption and EPR studies to produce directly the peroxo-bound myoglobin at 77 K. Annealing to temperatures near 185 K induces proton transfer, resulting in the formation of the hydroperoxo heme derivative. Resonance Raman studies of the annealed samples has permitted, for the first time, the direct observation of the key v(Fe-O) stretching mode of the physiologically important Fe-OOH fragment of this ubiquitous intermediate. The assignment of this mode to a feature appearing at 617 cm(-1) is strongly supported by documentation of a 25 cm(-1) shift to lower energy upon substitution with O-18(2) and by a 5 cm(-1) shift to lower energy for samples prepared in solutions of deuterated solvent.