Oxalate-dependent reductive activity of manganese peroxidase from Phanerochaete chrysosporium.
Oxalate-dependent reductive activity of manganese peroxidase from Phanerochaete chrysosporium.
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黄孢原毛平革菌锰过氧化物酶的草酸盐依赖性还原活性。
DOI：
10.1006/abbi.1994.1446
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发表时间：
1994
影响因子：
3.9
通讯作者：
Aust,SD
中科院分区：
文献类型：
--
作者：
Khindaria,A;Grover,TA;Aust,SD
研究了黄孢原毛平革菌(Phanerochaete Chrysosporium)锰依赖过氧化物酶(MNP)草酸依赖还原活性的机理。在含有Mn-过氧化物酶、Mn2+、草酸盐、双氧水、三氯化铁和1，10-邻菲咯啉的反应混合物中，铁被还原。只需要催化量的过氧化氢。在含有Mn-过氧化物酶、Mn2+、草酸盐和H_2O_2的反应混合物中也观察到氧的消耗，并被铁的加入所抑制。利用自旋陷阱5，5-二甲基-1-吡咯啉-N-氧化物和α-4-吡啶-1-氧化物-N-叔丁基硝酮的电子自旋共振研究，获得了在含有Mn2+、草酸盐和H_2O_2的反应混合物中产生甲酸盐自由基(CO_2−)和超氧化物(O_2−)的证据。结果表明，CO2−(厌氧条件)和O2−(好氧条件)均能还原铁离子。一些o.2−的错位会产生过氧化氢，以提供恒定的过氧化氢供应。
The mechanism of oxalate-dependent reductive activity of a manganese-dependent peroxidase (MnP) fromPhanerochaete chrysosporiumwas investigated. Ferric iron reduction was demonstrated in reaction mixtures containing Mn-peroxidase, Mn2+, oxalate, H2O2, ferric chloride, and 1,10-phenanthroline. Only catalytic amounts of H2O2were required. Oxygen consumption was also observed in reaction mixtures containing Mn-peroxidase, Mn2+, oxalate, and H2O2and was inhibited by the addition of ferric iron. Electron spin resonance studies, using the spin traps 5,5-dimethyl-1-pyrroline-N-oxide and α-4-pyridyl-1-oxide-N-t-butylnitrone were used to obtain evidence for the production of the formate radical (CO.2−) and superoxide (O.2−) in a reaction mixture containing Mn2+, oxalate and H2O2. It was concluded that both CO.2−(anaerobic conditions) and O.2−(aerobic conditions) could reduce ferric iron. The dismutation of some O.2−would produce H2O2to provide a constant supply of H2O2.