OXYGEN EFFECT ON DEOXYRIBONUCLEIC ACID INACTIVATION BY HYDROXYLAMINES
OXYGEN EFFECT ON DEOXYRIBONUCLEIC ACID INACTIVATION BY HYDROXYLAMINES
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DOI：
10.1021/bi00887a023
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发表时间：
1965-01-01
期刊：
影响因子：
2.9
通讯作者：
FREESE, EB
中科院分区：
文献类型：
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作者：
FREESE, E;FREESE, EB
羟胺 (HA) 及其一些含有游离 NOH 基团的衍生物对枯草芽孢杆菌的脱氧核糖核酸 (DNA) 的转化在高浓度 ([大于或等于 1 [图像]) 下主要产生诱变作用，在低浓度 (< 10-1 [图像]) 下主要产生灭活作用。灭活作用是由 HA 和 O2 之间反应的某些产物间接引起的，这些产物显然会产生硝酰基 (HNO)、过氧化氢 (H2O2) 和一些中间自由基。形成的过氧化物通过与HA的进一步反应再次被破坏。如果没有氧气，HA 产生的过氧化物和 HA 导致的转化 DNA 失活均不存在，并且可通过添加 EDTA、焦磷酸盐、KCN、FeCl3、过氧化氢酶或过氧化物酶来抑制。相同的试剂还可以抑制 H2O2 导致的 DNA 失活。因此，失活作用似乎是由 HA 以及硝酰基产生和破坏过氧化物过程中形成的自由基引起的。诱变作用不依赖于氧，也不受焦磷酸盐的抑制。它涉及 HA 基团与胞嘧啶的直接反应。这些结果解释了早期关于HA浓度依赖性失活和突变以及染色体断裂诱导的观察结果。
Hydroxyl-amine (HA) and some of its derivatives containing free NOH groups exert on transforming deoxyribonucleic acid (DNA) of Bacillus subtilis a predominantly mutagenic effect at high ([greater than or equ 1 [image]) and a predominantly inactivating effect at low (< 10-1 [image]) HA concentrations. The inactivating effect is indirectly caused by some product of the reaction between HA and O2 which apparently produces nitroxyl (HNO), hydrogen peroxide (H2O2), and several intermediate radicals. The formed peroxide is destroyed again by a further reaction with HA. Both the production of peroxide from HA and the inactivation of transforming DNA by HA are absent without oxygen and are inhibited by the addition of EDTA, pyro-phosphate, KCN, FeCl3, catalase, or peroxidase. The same agents also inhibit DNA inactivation by H2O2. The inactivating effect therefore seems to be caused by radicals formed during the production and destruction of peroxides by HA, and perhaps, in addition, by nitroxyl. The mutagenic effect does not depend on oxygen and is not inhibited by pyro- phosphate. It involves the direct reaction of HA groups with cytosine. These results explain earlier observations on the HA concentration dependence of inactivation and mutation and on the induction of chromosomal breaks.