THE DEMETHYLATION OF GUAIACOL BY A NEW BACTERIAL CYTOCHROME-P-450
THE DEMETHYLATION OF GUAIACOL BY A NEW BACTERIAL CYTOCHROME-P-450
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DOI：
10.1016/0003-9861(85)90662-9
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发表时间：
1985-01-01
影响因子：
3.9
通讯作者：
PELMONT, J
中科院分区：
文献类型：
--
作者：
DARDAS, A;GAL, D;PELMONT, J
用莫拉氏菌属的细胞色素P-450进行光谱研究，菌株GU 2，其可以愈创木酚或2-乙氧基苯酚作为唯一碳源和能量源生长。愈创木酚-细胞色素复合物的解离常数估计为0.15 μ M，如在体内或使用细胞可溶性提取物测定的。细胞色素P-450也可以结合2-乙氧基苯酚，2-丙氧基苯酚，和2-丁氧基苯酚，并在每种情况下的解离常数进行了测定。甲吡酮抑制全菌对愈创木酚的降解，并与愈创木酚竞争结合，常数约为0.8 mM。当生长在愈创木酚或2-乙氧基苯酚上时，细菌会分泌一些邻苯二酚。邻苯二酚和愈创木酚脱甲基的另一种产物甲醛被细菌进一步氧化。到目前为止，所有可用的数据是一致的细胞色素P-450在莫拉氏菌GU 2作为愈创木酚侧链的羟化酶，表现为一种非特异性O-脱烷基酶，具有广泛的特异性愈创木酚和同源化合物的侧链中具有较长的碳部分。
Spectroscopic studies were carried with a cytochrome P-450 in Moraxella sp., strain GU2, that could grow on guaiacol or 2-ethoxyphenol as the sole source of carbon and energy. The dissociation constant of the guaiacol-cytochrome complex was estimated to 0.15 .mu.M, as determined in vivo or using the cell soluble extract. Cytochrome P-450 could also bind 2-ethoxyphenol, 2-propoxyphenol, and 2-butoxyphenol and the dissociation constants were determined in each case. Metyrapone depressed the degradation of guaiacol by whole bacteria, and was bound competitively to guaiacol with a constant of about 0.8 mM. Some catechol was excreted by the bacteria when growing on either guaiacol or 2-ethoxyphenol. Catechol and the other product of guaiacol demethylation, formaldehyde, were further oxidized by the bacteria. All the data available so far are consistent with cytochrome P-450 in Moraxella GU2 as a hydroxylase for the guaiacol side chain, behaving as a nonspecific O-dealkylase with broad specificity for guaiacol and homologous compounds with a longer carbon part in the side chain.