Isolation and characterization of methanophenazine and function of phenazines in membrane-bound electron transport of Methanosarcina mazei Gol
Isolation and characterization of methanophenazine and function of phenazines in membrane-bound electron transport of Methanosarcina mazei Gol
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DOI：
10.1128/jb.180.8.2027-2032.1998
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发表时间：
1998-04-01
影响因子：
3.2
通讯作者：
Deppenmeier, U
中科院分区：
文献类型：
--
作者：
Abken, HJ;Tietze, M;Deppenmeier, U
用异辛烷萃取法从mazei Gol冻干膜中分离得到一种疏水氧化活性成分，分子量为538 Da，经高效液相色谱柱纯化后，用质谱和核磁共振分析了其化学结构。该组分被称为甲烷非那嗪，是一种2-氢非那嗪衍生物，通过醚桥连接到聚异戊二烯侧链。由于甲烷非那嗪几乎不溶于水缓冲液，因此测试了水溶性非那嗪衍生物与参与电子传递和能量守恒的膜结合酶相互作用的能力。以2-羟基非那嗪和2-溴非那嗪为电子受体时，纯化的F420H2脱氢酶活性最高。非那嗪-1-羧酸和非那嗪的效果较差。2-羟基非那嗪和非那嗪的K-m值分别为35 μ M和250 μ M。2-羟基吩那嗪也可以被f -420非反应性氢化酶催化的氢分子还原，这种酶存在于水洗膜制剂中。此外，膜结合的异二硫还原酶能够使用还原的2-羟基吩那嗪作为电子供体还原CoB-S-S-CoM。综上所述，我们有理由认为，在体内，甲烷非那嗪在马泽氏菌Go1的膜结合电子传递中发挥了重要作用。
A hydrophobic, redox-active component with a molecular mass of 538 Da was isolated from lyophilized membranes of Methanosarcina mazei Gol by extraction with isooctane, After purification on a high-performance liquid chromatography column, the chemical structure was analyzed by mass spectroscopy and nuclear magnetic resonance studies. The component was called methanophenazine and represents a 2-hydrophenazine derivative which is connected via an ether bridge to a polyisoprenoid side chain. Since methanophenazine was almost insoluble in aqueous buffers, water-soluble phenazine derivatives were tested for their ability to interact with membrane-bound enzymes involved in electron transport and energy conservation. The purified F420H2 dehydrogenase from M. mazei Go1 showed highest activity with 2-hydroxyphenazine and 2-bromophenazine as electron acceptors when F420H2 was added. Phenazine-1-carboxylic acid and phenazine proved to be less effective. The K-m values for 2-hydroxyphenazine and phenazine were 35 and 250 mu M, respectively. 2-Hydroxyphenazine was also reduced by molecular hydrogen catalyzed by an F-420-nonreactive hydrogenase which is present in washed membrane preparations. Furthermore, the membrane-bound heterodisulfide reductase was able to use reduced 2-hydroxyphenazine as an electron donor for the reduction of CoB-S-S-CoM. Considering all these results, it is reasonable to assume that methanophenazine plays an important role in vivo in membrane-bound electron transport of M. mazei Go1.