STRUCTURE OF FLAVIN-OXYGEN INTERMEDIATES INVOLVED IN ENZYMATIC-REACTIONS
STRUCTURE OF FLAVIN-OXYGEN INTERMEDIATES INVOLVED IN ENZYMATIC-REACTIONS
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DOI：
10.1111/j.1432-1033.1977.tb11579.x
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发表时间：
1977-01-01
期刊：
影响因子：
--
通讯作者：
HUSEIN, M
中科院分区：
文献类型：
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作者：
GHISLA, S;ENTSCH, B;HUSEIN, M
在黄素蛋白羟化酶和细菌荧光素酶的催化反应过程中，黄素过氧化物作为中间体形成，这在其他地方已有报道。据推测这些中间体是黄素辅酶的C(4a)衍生物。为了验证这一假设，合成了在异咯嗪环的C(4a)位置带有一个O取代基的修饰黄素辅酶。它们被猪肾D - 氨基酸氧化酶、荧光假单胞菌对羟基苯甲酸羟化酶和耻垢分枝杆菌乳酸氧化酶的脱辅基酶紧密结合；所形成的复合物显示出与羟化酶的瞬时O加合物非常相似的光谱特性。光黄素模型化合物的光谱高度依赖于溶剂环境和取代基的性质。在适当的条件下，它们能令人满意地模拟酶促瞬时O加合物的光谱。这些结果支持了这样的观点：在还原态酶与O₂反应时，这些黄素蛋白形成的初级O加合物是黄素C(4a)过氧化物。
During the catalytic reactions of flavoprotein hydroxylases and bacterial luciferase, flavin peroxides were formed as intermediates were reported elsewhere. These intermediates were postulated to be C(4a) derivatives of the flavin coenzyme. To test this hypothesis, modified flavin coenzymes carrying an O substituent at position C(4a) of the isoalloxazine ring were synthesized. They are tightly bound by the apoenzymes of pig kidney D-amino acid oxidase, Pseudomonas fluorescens p-hydroxybenzoate hydroxylase and Mycobacterium smegmatis lactate oxidase; the resulting complexes showed spectral properties closely similar to those of the transient O adducts of the hydroxylases. The optical spectra of the lumiflavin model compounds were highly dependent on the solvent environment and nature of the substituents. Under appropriate conditions they simulated satisfactorily the spectra of the transient enzymatic O adducts. The results supported the proposal that the primary O adducts formed with these flavoproteins on reaction of the reduced enzymes with O are flavin C(4a) peroxides.