Muntyan M S, Bloch D A, Dinarieva T Y, Drachev L A, Netrusov A I
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
Biochem Biophys Res Commun. 1994 Oct 14;204(1):428-35. doi: 10.1006/bbrc.1994.2476.
Two oxidases of the o-type in membranes of the methanol-grown obligate methylotroph Methylobacillus flagellatum KT were distinguished. For this purpose the kinetic analysis of the laser flash-induced optical absorbance changes of CO-oxidase complexes under reducing conditions was used. The ratio of these oxidases in membranes greatly depended on the phases of bacterial growth. One of the oxidases appeared to belong to the Escherichia coli o-type oxidase family being more sensitive to KCN (Ki = 1 microM). It showed monophasic CO recombination kinetics with tau 25-30 ms and was expressed in the early exponential phase of growth. The other oxidase seemed to be similar to the Bacillus sp. FTU o-type oxidase being less sensitive to KCN (Ki = 6 microM), having three-phasic CO reassociation kinetics with tau 35-70 microseconds, 0.25-0.5 ms and 2-4 ms and dominating in the stationary growth phase. Pyridine haemochrome spectra showed haems A and D to be absent from the bacterial membranes.
在甲醇培养的专性甲基营养菌鞭毛甲基芽孢杆菌KT的膜中，区分出了两种o型氧化酶。为此，采用了在还原条件下对激光闪光诱导的一氧化碳氧化酶复合物的光吸收变化进行动力学分析的方法。这些氧化酶在膜中的比例很大程度上取决于细菌生长阶段。其中一种氧化酶似乎属于大肠杆菌o型氧化酶家族，对氰化钾更敏感（抑制常数Ki = 1微摩尔）。它表现出单相关一氧化碳重组动力学，时间常数τ为25 - 30毫秒，且在生长的指数早期阶段表达。另一种氧化酶似乎与芽孢杆菌属FTU的o型氧化酶相似，对氰化钾不太敏感（抑制常数Ki = 6微摩尔），具有三相一氧化碳重新结合动力学，时间常数分别为35 - 70微秒、0.25 - 0.5毫秒和2 - 4毫秒，并且在稳定生长阶段占主导。吡啶血红素光谱显示细菌膜中不存在血红素A和D。
