Bauminger E R, Cohen S G, Dickson D P, Levy A, Ofer S, Yariv J
Biochim Biophys Acta. 1980 Jun 26;623(2):237-42. doi: 10.1016/0005-2795(80)90252-4.
57Fe Mössbauer spectra of whole frozen Escherichia coli cells and of an iron storage protein isolated from iron-rich cells of E. coli have been measured over a range of temperatures down to 0.08 K. The spectra of E. coli cells with high iron content and of the iron storage protein were found to be very similar. Above 4 K these spectra consist of a quadrupole split doublet characteristic of Fe3+. Below 3.5 K, the spectra display magnetic hyperfine splitting which is temperature dependent, and point to the existence of an ordered magnetic phase associated with a saturation magnetic hyperfine field of 43 tesla in both samples. The results indicate that the bulk of iron in the iron-rich cells is in the form of aggregates similar in nature to the iron cores in the isolated protein, although the latter account for not more than 1% of the total iron in the cells. The Mössbauer spectra of the isolated protein are different from those observed in ferritin, the iron-storage protein of plants and higher animals, showing that the iron cores in these two proteins are different.
在低至0.08 K的一系列温度范围内，测量了整个冷冻大肠杆菌细胞以及从富含铁的大肠杆菌细胞中分离出的一种铁储存蛋白的57Fe穆斯堡尔谱。发现高铁含量的大肠杆菌细胞和铁储存蛋白的谱非常相似。高于4 K时，这些谱由Fe3+特有的四极分裂双峰组成。低于3.5 K时，谱显示出与温度相关的磁超精细分裂，表明在两个样品中都存在与43特斯拉的饱和磁超精细场相关的有序磁相。结果表明，富含铁的细胞中的大部分铁以与分离出的蛋白质中的铁芯性质相似的聚集体形式存在，尽管后者在细胞总铁中所占比例不超过1%。分离出的蛋白质的穆斯堡尔谱与植物和高等动物的铁储存蛋白铁蛋白中观察到的谱不同，表明这两种蛋白质中的铁芯不同。
