Goldammer E V, Wenzel H, Zorn H
Biochim Biophys Acta. 1978 Sep 21;543(1):63-71. doi: 10.1016/0304-4165(78)90454-3.
Proton spin-lattice relaxation times of pyridine and 1-methylimidazole complexed on Fe(III)protoporphyrin IX dimethyl ester, Fe(III)tetraphenylporphyrin in chloroform and on metmyoglobin in 2H2O have been measured. Caused by chemical exchange of the ligand molecules into the bulk solvent phase, the decay of their MZ-magnetization is given by a superposition of two exponentials from which the mean lifetime of the complexed species can be determined. This method offers the possibility to study exchange kinetics of ligand molecules from a well defined molecular configuration. The present data are compared with the results from linewidth measurements of the bulk phase molecules. From both sets of parameters a detailed picture of the ligand exchange can be gained, particularly if spin transition of the paramagnetic organic metal complex occurs, as is the case for some ferriporphyrins. For metmyoglobin, the NMR result is compared with relaxation times extracted from temperature jump experiments under similar conditions.
已测量了吡啶和1-甲基咪唑与氯仿中的Fe(III)原卟啉IX二甲酯、Fe(III)四苯基卟啉以及重水中的高铁肌红蛋白络合时的质子自旋-晶格弛豫时间。由于配体分子向本体溶剂相的化学交换，它们的Mz磁化强度的衰减由两个指数的叠加给出，从中可以确定络合物种的平均寿命。这种方法为研究来自明确分子构型的配体分子的交换动力学提供了可能性。将目前的数据与本体相分子线宽测量的结果进行了比较。从这两组参数中可以获得配体交换的详细情况，特别是当顺磁性有机金属络合物发生自旋跃迁时，一些铁卟啉就是这种情况。对于高铁肌红蛋白，将核磁共振结果与在类似条件下从温度跳跃实验中提取的弛豫时间进行了比较。
