Maltempo M M
Biochim Biophys Acta. 1975 Jan 30;379(1):95-102. doi: 10.1016/0005-2795(75)90011-2.
Recent magnetic studies have shown that in the pH range 1 to 11 the bacterial heme protein ferricytochrome c' can undergo reversible transitions between various pure high-spin and quantum mechanically mixed (intermediate and high)-spin protein states. The EPR data presented here extend the recent work to high alkaline pH and show that above pH 11.6 reversible transitions occur between various pure high-spin and pure low-spin protein states. The new data and the previous magnetic studies of the protein are discussed in the context of the entatic nature of the iron-porphyrin complex in ferricytochrome c'. EPR data are also provided concerning an anomalous, but reversible, transition to a protein state with reduced heme iron, triggered by freezing and thawing at physiological pH.
最近的磁性研究表明，在pH值为1至11的范围内，细菌血红素蛋白高铁细胞色素c'可在各种纯高自旋和量子力学混合（中自旋和高自旋）蛋白状态之间发生可逆转变。本文给出的电子顺磁共振（EPR）数据将近期的研究扩展到了高碱性pH值范围，并表明在pH值高于11.6时，各种纯高自旋和纯低自旋蛋白状态之间会发生可逆转变。结合高铁细胞色素c'中铁卟啉复合物的内禀态性质，对该蛋白的新数据和先前的磁性研究进行了讨论。还提供了有关在生理pH值下通过冻融引发的异常但可逆地转变为血红素铁含量降低的蛋白状态的EPR数据。
