CATALYSIS OF SUPEROXIDE DISMUTATION BY MANGANESE AMINOPOLYCARBOXYLATE COMPLEXES
CATALYSIS OF SUPEROXIDE DISMUTATION BY MANGANESE AMINOPOLYCARBOXYLATE COMPLEXES
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DOI：
10.1016/0003-9861(86)90368-1
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发表时间：
1986-12-01
影响因子：
3.9
通讯作者：
RUSH, JD
中科院分区：
文献类型：
--
作者：
KOPPENOL, WH;LEVINE, F;RUSH, JD
锰、铜、钴和铁与各种氨基聚羧酸盐的配合物，浓度从2。10-7到3次。以马铁细胞色素c为超氧化物竞争试剂，对10 ~ 6 M进行了超氧化物歧化酶活性测定。过量配体存在时，硝酸三乙酸锰和乙二胺二乙酸锰的催化活性为2.2倍。107和1.8倍。pH为6、22时，分别为107 M-1 s-1。1.学位。C，离子强度10mm。这些速率常数在较高的ph值下显著降低。n -羟乙基乙二胺三乙酸锰被超氧化物氧化，但似乎没有催化活性。从上述两种配合物表现出催化作用的实验条件和其他金属螯合物的不活性可以得出结论，开放配位对于催化失配反应是必要的，但不是充分的。
Complexes of manganese, copper, cobalt, and iron with a variety of aminopolycarboxylates at concentrations from 2 .times. 10-7 to 3 .times. 10-6 M were tested for superoxide dismutase activity with horse ferricytochrome c as the competing reagent for superoxide. In the presence of excess ligand only manganous nitrilotriacetate and manganous ethylenediaminediacetate showed activity with catalytic rate constants of 2.2 .times. 107 and 1.8 .times. 107 M-1 s-1, respectively, at pH 6, 22 .+-. 1.degree. C, and 10 mM ionic strength. These rate constants decrease considerably at higher pH. Manganous N-hydroxyethylethylenediaminetriacetate is oxidized by superoxide, but does not appear to have catalytic activity. From the experimental conditions under which the two complexes mentioned above exhibit catalysis, and the inactivity of other metal chelates, it is concluded that an open coordination site is essential but not sufficient to catalyze the dismutation reaction.