Auer G, Mayer B, Wastyn M, Fromwald S, Eghbalzad K, Alge D, Peschek G A
Institute of Physical Chemistry, University of Vienna, Austria.
Biochem Mol Biol Int. 1995 Dec;37(6):1173-85.
The cyanobacteria Nostoc sp. strain Mac, Anabaena 7937, Synechocystis 6803, and Anacystis nidulans (Synechococcus 6301) were grown and incubated in the light under three different oxygen regimes: Phase-A cells were harvested from photoautotrophically growing cultures at a cell density of 2.8-3.2 microliter packed cell mass/ml and an oxygen concentration of approx. 350 microM (corresponding to > 150% air saturation). Phase-B cells were harvested 24 hrs after 20 microM 3-(3,4-dichlorophyl)-1,1-dimethylurea had been added to the culture and gassing switched to 1% oxygen (< 10 microM). Phase-C cells originated from phase-B cells after 12 hrs of gassing the illuminated, yet non-growing cultures with air (21% oxygen or 200-220 microM in the medium). Cytoplasmic membranes were isolated and purified from each of the three cell types. Non-covalently bound hemes were extracted and identified by reversed-phase high performance liquid chromatography. Besides ubiquitous heme B only heme A was detected in phase-A membranes while phase-B and phase-C membranes contained both hemes A and O proportions of which depended on the oxygen status of the cells. CO/difference spectra, photo-action spectra of CO-inhibited oxygen uptake, and polarographic determination of oxygen-affinities clearly showed that both hemes A and O were part of a functional form of cytochrome-c oxidase which, however, exhibited a single subunit-I apoprotein as verified by immunoblotting. Also electron transport characteristics did not give evidence for a quinol or any other alternate oxidase functioning in cyanobacteria.
蓝藻念珠藻属菌株Mac、鱼腥藻7937、聚球藻6803和巢状织线藻（聚球藻6301）在三种不同的氧气条件下于光照下培养和孵育：A期细胞从光自养生长的培养物中收获，细胞密度为2.8 - 3.2微升压实细胞团/毫升，氧气浓度约为350微摩尔（相当于>150%空气饱和度）。在向培养物中添加20微摩尔3-(3,4-二氯苯基)-1,1-二甲基脲并将通气改为1%氧气（<10微摩尔）24小时后收获B期细胞。C期细胞源自B期细胞，在对光照但不生长的培养物通气12小时（空气中21%氧气或培养基中200 - 220微摩尔）后获得。从这三种细胞类型中分离并纯化细胞质膜。通过反相高效液相色谱法提取并鉴定非共价结合的血红素。除了普遍存在的血红素B外，在A期膜中仅检测到血红素A，而B期和C期膜中同时含有血红素A和O，其比例取决于细胞的氧气状态。CO/差光谱、CO抑制的氧气摄取的光作用光谱以及氧亲和力的极谱测定清楚地表明，血红素A和O都是细胞色素c氧化酶功能形式的一部分，然而，通过免疫印迹证实其呈现单个亚基-I载脂蛋白。电子传递特性也没有为蓝藻中发挥作用的喹啉或任何其他交替氧化酶提供证据。
