CO DEHYDROGENASE AND ACETOCLASTIC METHANOGENESIS IN METHANOSARCINA BARKERI

巴克甲烷八球菌中的 CO 脱氢酶和乙酰分解产甲烷作用

• 批准号: 3942770
• 负责人: D A GRAHAME
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3942770
• 关键词: Methanobacteriaceae; acetates; carbon monoxide; enzyme structure; iron; microorganism culture; microorganism metabolism; nickel; tissue /cell culture

Large quantities of purified carbon monoxide dehydrogenase (CODH) have been obtained from acetate-grown cells of Methanosarcina barkeri by scaling up the purification procedure which we developed in 1985. Studies on the pure enzyme demonstrated that it has an alpha 2 beta 2 oligomeric structure composed of subunits with molecular weights of 19,700 and 84,500. Analysis of the metal ion content indicated 1.3 plus or minus 0.3 (n=4) Ni and 15.6 plus or minus 5.6 (n=5) Fe per mol alpha 2 beta 2. Dialysis against EDTA did not reduce the content of these metals. The enzyme did not contain Co or Mo. The amino acid compositions of the subunits were determined. The enzyme did not catalyze isotopic exchange between (1- C14)acetyl-CoA and Co. Ferredoxin, FAD, FMN, 2,3,5- triphenyltetrazolium chloride (TTC), methyl viologen, and phenazine methosulfate served as electron acceptors; however, the enzyme did not reduce NAD, NADP, or the 8-hydroxy-5- deazaflavin factor F-420. A higher degree of thermostability was noted in the absence than in the presence of CO. Pure CODH from Methanococcus vannielii was also found to be an alpha 2 beta 2 oligomer composed of subunits which were similar in molecular weights to the subunits of M. barkeri CODH.

大量纯化的一氧化碳脱氢酶 （CODH）已从乙酸盐生长的细胞中获得， 巴氏甲烷八叠球菌的放大纯化 我们在1985年开发的。 纯酶的研究 证明了它具有α 2 β 2寡聚体结构 由分子量为19，700的亚基组成， 84,500. 金属离子含量的分析表明1.3加或 -0.3（n=4）Ni和15.6 ± 5.6（n=5）Fe/mol α 2 β 2 EDTA透析并没有减少 这些金属的含量。 该酶不含Co或Mo。 测定了各亚基的氨基酸组成。 该酶不催化（1- C14）乙酰辅酶A和Co.铁氧还蛋白，FAD，FMN，2，3，5- 氯化三苯基四唑（TTC），甲基紫精，和 吩嗪硫酸甲酯用作电子受体;然而， 这种酶不减少NAD、NADP或8-羟基-5- 脱氮黄素因子F-420。 更高的热稳定性 在没有CO的情况下比在CO的存在下注意到。 来自范氏甲烷球菌的CODH也被发现是一种 α 2 β 2寡聚体由亚基组成， 与M的亚基分子量的关系。barkeri CODH.