Preparation and O2 binding study of myoglobin having a cobalt porphycene.
Preparation and O2 binding study of myoglobin having a cobalt porphycene.
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DOI：
10.1021/ic0513639
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发表时间：
2005-11
影响因子：
4.6
通讯作者：
T. Matsuo;T. Tsuruta;K. Maehara;Hideaki Sato;Y. Hisaeda;Takashi Hayashi
中科院分区：
文献类型：
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作者：
T. Matsuo;T. Tsuruta;K. Maehara;Hideaki Sato;Y. Hisaeda;Takashi Hayashi
为了研究钴卟烯在蛋白质基质中的反应性，用 2,7-二乙基-3,6,12,17-四甲基-13,16-双（羧乙基）卟啉钴 (II) 重建抹香鲸肌红蛋白（一种储氧血红蛋白）。与先前报道的具有铁卟啉的肌红蛋白的发现类似，具有钴卟啉的重构肌红蛋白也被发现具有比具有钴原卟啉IX的肌红蛋白大2个数量级的O2亲和力。具有钴卟啉的脱氧和氧肌红蛋白在 77 K 下的 EPR 光谱也具有与具有钴原卟啉 IX 的肌红蛋白相似的特征。这些光谱表明，脱氧形式的卟啉钴由一个假设为 His93 的咪唑环的含氮配体配位，并且 CoII-O2 的键构型被认为是 CoIII-Omicron2*- 物种。
Sperm whale myoglobin, an oxygen-storage hemoprotein, was reconstituted with 2,7-diethyl-3,6,12,17-tetramethyl-13,16-bis(carboxyethyl)porphycenatocobalt(II) in order to investigate the reactivities of a cobalt porphycene in a protein matrix. Similar to the previously reported finding for the myoglobin with the iron porphycene, the reconstituted myoglobin with the cobalt porphycene was also found to have an O2 affinity 2 orders of magnitude greater than that of the myoglobin possessing cobalt protoporphyrin IX. The EPR spectra of the deoxy and oxy myoglobins having the cobalt porphycene at 77 K also have features similar to those of the myoglobin with cobalt protoporphyrin IX. These spectra suggest that the porphycene cobalt in the deoxy form is coordinated by one nitrogenous ligand postulated to be the imidazole ring of His93, and that the bond configuration of CoII-O2 is regarded as the CoIII-Omicron2*- species.