EFFECT OF HYDROGEN PEROXIDE ON GLUCOSE OXIDASE FROM ASPERGILLUS NIGER
EFFECT OF HYDROGEN PEROXIDE ON GLUCOSE OXIDASE FROM ASPERGILLUS NIGER
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DOI：
10.1021/bi00865a018
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发表时间：
1966-01-01
期刊：
影响因子：
2.9
通讯作者：
KLEPPE, K
中科院分区：
文献类型：
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作者：
KLEPPE, K
在pH 5.8和25[degree]下研究了H2 O2对黑曲霉黄素酶葡萄糖氧化酶的影响。该酶被H2 O2灭活。还原形式对H2 O2更敏感，并且比氧化形式更容易失活至少100倍。还原形式的失活速率不依赖于D-葡萄糖的浓度。对失活酶的性质也进行了研究。失活葡萄糖氧化酶的分子量与未处理的酶相同，而光谱略有不同。然而，在游离黄素腺嘌呤二核苷酸组从酶中释放出来后，没有检测到化学变化。氨基酸分析表明，当氧化和还原的葡萄糖氧化酶与H2 O2在相同的条件下处理略多蛋氨酸亚砜被发现在还原H2 O2处理的酶比在氧化H2 O2处理的酶。因此，这表明酶的失活涉及位于或接近活性位点的某些甲硫氨酸残基的修饰。对还原酶失活的可能机制进行了讨论。
The effect of H2O2 on the flavoenzyme glucose oxidase from Aspergillus niger has been studied at pH 5.8 and 25[degree]. The enzyme is inactivated by H2O2. The reduced form is much more sensitive to H2O2 and is inactivated at least 100 times more readily than the oxidized form. The rate of inactivation of the reduced form is not dependent on the concentration of D-glucose. Properties of the inactive enzyme have also been studied. The molecular weight of the inactive glucose oxidase is the same as for the untreated enzyme, whereas the spectrum differs slightly. However, no chemical alterations were detected in the free flavin-adenine dinucleotide group after it had been released from the enzyme. Amino acid analysis showed that when oxidized and reduced glucose oxidase were treated with H2O2 under identical conditions slightly more methionine sulfoxide was found in the reduced H2O2-treated enzyme than in the oxidized H2O2-treated enzyme. It is therefore suggested that the inactivation of the enzyme involves modification of certain methionine residues located at or near the active site. Possible mechanisms for the inactivation of the reduced enzyme are discussed.