Keller R M, Wüthrich K, Schejter A
Biochim Biophys Acta. 1977 Apr 25;491(2):409-15. doi: 10.1016/0005-2795(77)90283-5.
The coordination of the heme iron in cytochrome c-552 from Euglena gracilis was investigated by 1H NMR studies at 360 MHz. The data imply that the axial heme ligands are His-14 and Met-56 in both the oxidized and the reduced protein. Studies of mixed solutions of ferro- and ferricytochrome c-552, which provided much of the information on the heme structure, also showed that the intermolecular electron exchange is characterized by a bimolecular rate constant of 5-10(6) mol-1-s-1 at 29 degrees C, which is three orders of magnitude faster than the corresponding reaction in solutions of mammalian cytochromes c.
通过在360兆赫下的1H核磁共振研究，对纤细裸藻细胞色素c - 552中的血红素铁配位进行了研究。数据表明，在氧化态和还原态蛋白质中，轴向血红素配体均为His - 14和Met - 56。对亚铁细胞色素c - 552和高铁细胞色素c - 552混合溶液的研究提供了许多关于血红素结构的信息，该研究还表明，在29摄氏度时，分子间电子交换的双分子速率常数为5 - 10(6)摩尔-1 -秒-1，这比哺乳动物细胞色素c溶液中的相应反应快三个数量级。
