LINKAGE OF FORMATE HYDROGENLYASE WITH ANAEROBIC RESPIRATION IN PROTEUS-MIRABILIS
LINKAGE OF FORMATE HYDROGENLYASE WITH ANAEROBIC RESPIRATION IN PROTEUS-MIRABILIS
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DOI：
10.1016/0005-2728(82)90254-7
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发表时间：
1982-01-01
期刊：
影响因子：
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通讯作者：
STOUTHAMER, AH
中科院分区：
文献类型：
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作者：
KRAB, K;OLTMANN, LF;STOUTHAMER, AH
研究了厌氧培养奇异假单胞菌完整细胞中催化甲酸氢解酶的酶系统与参与厌氧呼吸的还原酶之间的联系。在所有生长条件下，H2或甲酸盐都可以还原硝酸盐和富马酸；四硫酸盐和硫代硫酸盐的还原只发生在生长后期从pH调节的分批培养中收获的细胞，而不发生在生长早期收获的细胞或在pH恒定培养中生长的细胞中。在所有条件下，细胞都具有四硫酸盐还原酶。四硫酸盐还原酶(也催化硫代硫酸盐的还原)和甲酸氢解酶链之间的联系取决于生长条件。在甲酸盐还原高电势氧化剂富马酸、四硫酸根(如果可能)或人工电子受体亚甲基蓝的过程中，由于甲酸酸氢解酶反应，没有同时放氢。氢气生产只有在亚甲基蓝或富马酸完全还原后才开始，亚甲基蓝在没有气体产生的滞后阶段后才开始生产。在富马酸还原活性较低的制剂中，这伴随着二氧化碳生产的加速。在甲酸盐还原硫代硫酸盐(一种低电势氧化剂)或四硫酸根在苯基紫精(一种低电势介体)存在的过程中，氢气同时生成。甲酸氢解酶显然受到一个因子的调节，该因子响应存在的任何电子受体对的氧化还原状态，使得当受体对被氧化到太大程度时，裂解酶的活性被阻止。
The linkage between the enzyme system catalyzing formate hydrogenlyase and reductases involved in anaerobic respiration in intact cells of anaerobically grown P. mirabilis was studied. Reduction of nitrate and fumarate by H2 or formate was possible under all growth conditions; reduction of tetrathionate and thiosulfate occurred only in cells harvested at late growth phase from a pH-regulated batch culture and not in cells harvested at early growth phase or in cells grown in pH-auxostat culture. Under all conditions, cells possessed the enzyme tetrathionate reductase. Linkage between tetrathionate reductase (catalyzing also reduction of thiosulfate) and the formate hydrogenlyase chain is dependent on growth conditions. During reduction of high-potential oxidants such as fumarate, tetrathionate (when possible) or the artificial electron acceptor methylene blue by formate, there was no simultaneous H2 evolution due to the formate hydrogenlyase reaction. H2 production started only after complete reduction of methylene blue or fumarate, in the case of methylene blue after a lag phase without gas production. In preparations with a low fumarate reduction activity this was accompanied by an acceleration in CO2 production. During reduction of thiosulfate (a low-potential oxidant) or of tetrathionate in the presence of benzyl viologen (a low-potential mediator) by formate, H2 was evolved simultaneously. Formate hydrogenlyase is apparently regulated by a factor that responds to the redox state of any electron acceptor couple present such that lyase activity is blocked when the acceptor couple is oxidized to too great an extent.