Properties of electron carriers in the process of methanol oxidation in a new restricted facultative marine methylotrophic bacterium, Methylophaga sp. MP
Properties of electron carriers in the process of methanol oxidation in a new restricted facultative marine methylotrophic bacterium, Methylophaga sp. MP
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新型限制性兼性海洋甲基营养菌甲基噬菌体甲醇氧化过程中电子载体的特性。
DOI：
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发表时间：
2002
影响因子：
2.8
通讯作者：
S. Kim
中科院分区：
文献类型：
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作者：
Moonjoo Koh;C. Kim;Y. Kim;H. Choi;E. H. Cho;Eungbin Kim;Youngmin Kim;S. Kim
对海洋甲醇氧化菌Methylophaga sp. MP中甲醇脱氢酶（MDH）和c型细胞色素进行了纯化和表征。天然MDH分子量为148 kDa，等电点为5.5。发现c型细胞色素c L和c H，其等电点分别为3.4和8.0。纯化的MDH比其他土壤甲基营养细菌具有更高的热稳定性。MDH向细胞色素c L的电子流速率高于MDH向细胞色素c H的电子流速率，说明MDH的生理一级电子受体是细胞色素c L。在两种染料（PES/DCPIP）连接的检测体系中，MDH向苯那嗪乙硫代硫酸钠（PES，人工电子受体）的电子转移不受NaCl的抑制，而在细胞色素/DCPIP连接的检测体系中，MDH向细胞色素c L的电子转移受NaCl的显著抑制。EDTA等金属螯合剂对MDH活性有相同的影响。
Methanol dehydrogenase (MDH) and c-type cytochromes from marine methanol-oxidizing bacterium, Methylophaga sp. MP, were purified and characterized. The native MDH had a molecular mass of 148 kDa and its isoelectric point was 5.5. Two c-type cytochromes, c L and c H , were found, and their isoelectric points were 3.4 and 8.0, respectively. The purified MDH had higher thermal stability than that of the other soil methylotrophic bacteria. The electron flow rate from MDH to cytochrome c L was higher than that from MDH to cytochrome c H , indicating that the physiological primary electron acceptor for MDH is cytochrome c L . The electron transfer from MDH to phenazine ethosulfate (PES, artificial electron acceptor) in the two dye (PES/DCPIP)-linked assay system was not inhibited by NaCl, whereas the electron flow from MDH to cytochrome c L in the cytochrome/ DCPIP-linked assay system was suppressed significantly by NaCl. Metal chelating agents such as EDTA showed the same effects on the MDH activity.