Matsushita K, Takahashi K, Takahashi M, Ameyama M, Adachi O
Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University.
J Biochem. 1992 Jun;111(6):739-47. doi: 10.1093/oxfordjournals.jbchem.a123829.
Acetobacter methanolicus is a unique acetic acid bacterium which has a methanol oxidase respiratory chain, as seen in methylotrophs, in addition to its ethanol oxidase respiratory chain. In this study, the relationship between methanol and ethanol oxidase respiratory chains was investigated. The organism is able to grow by oxidizing several carbon sources, including methanol, glycerol, and glucose. Cells grown on methanol exhibited a high methanol-oxidizing activity and contained large amounts of methanol dehydrogenase and soluble cytochromes c. Cells grown on glycerol showed higher oxygen uptake rate and dehydrogenase activity with ethanol but little methanol-oxidizing activity. Furthermore, two different terminal oxidases, cytochrome c and ubiquinol oxidases, have been shown to be involved in the respiratory chain; cytochrome c oxidase predominates in cells grown on methanol while ubiquinol oxidase predominates in cells grown on glycerol. Both terminal oxidases could be solubilized from the membranes and separated from each other. The cytochrome c oxidase and the ubiquinol oxidase have been shown to be a cytochrome co and a cytochrome bo, respectively. Methanol-oxidizing activity was diminished by several treatments that disrupt the integrity of the cells. The activity of the intact cells was inhibited with NaCl and/or EDTA, which disturbed the interaction between methanol dehydrogenase and cytochrome c. Ethanol-oxidizing activity in the membranes was inhibited with 2-heptyl-4-hydroxyquinoline N-oxide, which inhibited ubiquinol oxidase but not cytochrome c oxidase. Alcohol dehydrogenase has been purified from the membranes of glycerol-grown cells and shown to reduce ubiquinone-10 as well as a short side-chain homologue in detergent solution.(ABSTRACT TRUNCATED AT 250 WORDS)
甲醇醋杆菌是一种独特的醋酸菌，除了具有乙醇氧化酶呼吸链外，还具有甲醇氧化酶呼吸链，这在甲基营养菌中可见。在本研究中，对甲醇和乙醇氧化酶呼吸链之间的关系进行了研究。该微生物能够通过氧化多种碳源生长，包括甲醇、甘油和葡萄糖。在甲醇上生长的细胞表现出高甲醇氧化活性，并含有大量甲醇脱氢酶和可溶性细胞色素c。在甘油上生长的细胞对乙醇显示出更高的氧摄取率和脱氢酶活性，但甲醇氧化活性很低。此外，已证明两种不同的末端氧化酶，即细胞色素c氧化酶和泛醇氧化酶，参与呼吸链；细胞色素c氧化酶在以甲醇为碳源生长的细胞中占主导地位，而泛醇氧化酶在以甘油为碳源生长的细胞中占主导地位。两种末端氧化酶都可以从膜中溶解并彼此分离。已证明细胞色素c氧化酶和泛醇氧化酶分别是细胞色素co和细胞色素bo。几种破坏细胞完整性的处理降低了甲醇氧化活性。完整细胞的活性被NaCl和/或EDTA抑制，这干扰了甲醇脱氢酶与细胞色素c之间的相互作用。膜中的乙醇氧化活性被2-庚基-4-羟基喹啉N-氧化物抑制，该物质抑制泛醇氧化酶但不抑制细胞色素c氧化酶。乙醇脱氢酶已从甘油生长细胞的膜中纯化出来，并显示在去污剂溶液中能还原泛醌-10以及一种短侧链同系物。（摘要截短于250字）
