Co⁺ | 16610-75-6

• 分子结构分类: 无机化合物 - 均相金属化合物 - 均相过渡金属化合物
• 英文名称: Co⁺
• CAS: 16610-75-6
• 化学式: Co
• 分子量: 58.93265
• InChiKey: BFVNPAKTAJENJQ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.0
• 重原子数：
  1.0
• 可旋转键数：
  0.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  Co⁺ 、 甲硫醇 生成 硫化氢 、 methyl-Co(III)
  参考文献：
  名称：

  甲烷化甲烷八叠球菌的甲硫醇：辅酶M甲基转移酶的MtsA亚基催化类固醇依赖性二甲基硫醚：辅酶M甲基转移的两个半反应。

  摘要：

  由二甲基硫的甲烷生成需要辅酶M的中间甲基化。此反应由甲基硫醇：辅酶M甲基转移酶催化，该酶由两个多肽MtsA（一种甲基钴胺素：辅酶M甲基转移酶）和MtsB（与参与甲烷化作用的一类类rinrinoid蛋白同源）催化。纯化了重组MtsA，发现其是同型二聚体，每个多肽结合一个锌原子，但没有类corrinoid辅因子。MtsA是一种活性的甲基钴胺素：辅酶M甲基转移酶，也可以与二甲基硫醚化钴（I）丙氨酸，在等当量反应的K（eq）为5 x 10（-）（4）的情况下产生等摩尔的甲基钴胺素和甲硫醇。在完全不存在MtsB的情况下，MtsA和Cob（I）阿拉明可介导二甲基硫醚：辅酶M的甲基转移。二甲基硫醚抑制甲基钴胺素：MtsA进行辅酶甲基转移。二甲基硫醚与甲基钴胺素的抑制作用混合在一起，但与辅酶M竞争.MtbA是参与甲胺辅酶M甲基化的MtsA同源物，未被二甲基硫醚抑制，也没有催化可检测的二甲基硫醚：钴（I）丙

  DOI：

  10.1074/jbc.m007514200
• 作为产物：
  描述：

  5,6,7,8-Tetrahydrosarcinapterin(4-) 、 methyl-Co(III) 生成 5-Methyltetrahydrosarcinapterin(4-) 、 Co⁺ 、 氢(+1)阳离子
  参考文献：
  名称：

  Characterization of the cdhD and cdhE genes encoding subunits of the corrinoid/iron-sulfur enzyme of the CO dehydrogenase complex from Methanosarcina thermophila

  摘要：

  来自Methanosarcina thermophila的CO脱氢酶酶复合物包含由两个亚基（δ和γ）组成的酰基/铁硫酶酶。编码δ和γ亚基的cdhD和cdhE基因已被克隆和测序。cdhD基因位于cdhE的上游，并相隔3个bp。两个基因都以明显的核糖体结合位点为前导。北方（RNA）印迹和引物延伸分析表明，cdhD和cdhE是从位于cdhD数千个碱基上游的启动子中共同转录的。假定的CdhD和CdhE序列与Clostridium thermoaceticum的酰基/铁硫酶酶β和α亚基编码基因推导的序列相似度为37％。CdhE序列具有一个四硫氨酸基序列，具有通过电子顺磁共振光谱鉴定的潜在结合4Fe-4S簇的能力。使用T7 RNA聚合酶/启动子系统在大肠杆菌中独立产生CdhD和CdhE。纯化的CdhD蛋白以base-on构型与羟基钴胺再生。纯化的CdhE蛋白具有Fe-S中心和base-off钴胺结合，其中苯并咪唑碱基氮原子不再是钴原子的低轴配体。

  DOI：

  10.1128/jb.178.2.340-346.1996

文献信息

• Reconstitution of Dimethylamine:Coenzyme M Methyl Transfer with a Discrete Corrinoid Protein and Two Methyltransferases Purified fromMethanosarcina barkeri
  作者：Donald J. Ferguson、Natalia Gorlatova、David A. Grahame、Joseph A. Krzycki

  DOI：10.1074/jbc.m910218199

  日期：2000.9

  methylation with dimethylamine. MtbB1 methylated either corrinoid bound to MtbC or free cob(I)alamin with dimethylamine, indicating MtbB1 carries an active site for dimethylamine demethylation and corrinoid methylation. Experiments in which different proteins of the resolved monomethylamine:coenzyme M methyl transfer reaction replaced proteins involved in dimethylamine:coenzyme M methyl transfer indicated

  从二甲胺到辅酶M的甲基转移首次仅使用高度纯化的蛋白质在体外进行了重建。这些从巴氏甲烷八叠球菌分离出的蛋白质包括以前未鉴定的类皮质醇蛋白MtbC，该蛋白与MtbA共同纯化，MtbA是对甲基胺类甲烷化作用特异的甲基类皮质醇：辅酶M甲基转移酶。MtbC在细胞提取物中结合1.0 mol类海藻素辅因子/ mol 24-kDa多肽和刺激的二甲胺：辅酶M甲基转移3.4倍。纯化的MtbC和MtbA用于分析和纯化二甲胺：类雌激素甲基转移酶MtbB1。MtbB1是一个230 kDa的蛋白质，由不具有corrinoid修复基团的51 kDa的亚基组成。纯化的MtbB1，MtbC和MtbA是体外二甲胺：辅酶M甲基转移的唯一蛋白质要求。MtbB1：MtbC比为1时最适合用二甲胺进行辅酶M甲基化。MtbB1用二甲胺甲基化结合到MtbC的类固醇或游离的Cob（I）alamin，表明MtbB1带有一个用于二甲胺脱甲基和类
• Reconstitution of trimethylamine-dependent coenzyme M methylation with the trimethylamine corrinoid protein and the isozymes of methyltransferase II from Methanosarcina barkeri
  作者：D J Ferguson、J A Krzycki

  DOI：10.1128/jb.179.3.846-852.1997

  日期：1997.2

  Reconstitution of trimethylamine-dependent coenzyme M (CoM) methylation was achieved with three purified polypeptides. Two of these polypeptides copurified as a trimethylamine methyl transfer (TMA-MT) activity detected by stimulation of the TMA:CoM methyl transfer reaction in cell extracts. The purified TMA-MT fraction stimulated the rate of methyl-CoM formation sevenfold, up to 1.7 micromol/min/mg of TMA-MT protein. The TMA-MT polypeptides had molecular masses of 52 and 26 kDa. Gel permeation of the TMA-MT fraction demonstrated that the 52-kDa polypeptide eluted with an apparent molecular mass of 280 kDa. The 26-kDa protein eluted primarily as a monomer, but some 26-kDa polypeptides also eluted with the 280-kDa peak, indicating that the two proteins weakly associate. The two polypeptides could be completely separated using gel permeation in the presence of sodium dodecyl sulfate. The corrinoid remained associated with the 26-kDa polypeptide at a molar ratio of 1.1 corrin/26-kDa polypeptide. This polypeptide was therefore designated the TMA corrinoid protein, or TCP. The TMA-MT polypeptides, when supplemented with purified methylcorrinoid:CoM methyltransferase (MT2), could effect the demethylation of TMA with the subsequent methylation of CoM and the production of dimethylamine at specific activities of up to 600 nmol/min/mg of TMA-MT protein. Neither dimethylamine nor monomethylamine served as the substrate, and the activity required Ti(III) citrate and methyl viologen. TMA-MT could interact with either isozyme of MT2 but had the greatest affinity for the A isozyme. These results suggest that TCP is uniquely involved in TMA-dependent methanogenesis, that this corrinoid protein is methylated by the substrate and demethylated by either isozyme of MT2, and that the predominant isozyme of MT2 found in TMA-grown cells is the favored participant in the TMA:CoM methyl transfer reaction.

  使用三种纯化的多肽重新组装了三甲胺依赖性辅酶M（CoM）甲基化。其中两种多肽作为三甲胺甲基转移（TMA-MT）活性一起纯化，通过刺激细胞提取物中TMA：CoM甲基转移反应来检测。纯化的TMA-MT分数将甲基-CoM形成速率提高了七倍，最高可达每毫克TMA-MT蛋白1.7微摩尔/分钟。TMA-MT多肽的分子量为52和26 kDa。 TMA-MT分数的凝胶透析表明，52 kDa多肽在表观分子量为280 kDa的条件下洗脱。26 kDa蛋白主要以单体形式洗脱，但有些26 kDa多肽也与280 kDa峰一起洗脱，表明这两种蛋白质弱结合。在十二烷基硫酸钠存在下，可以完全分离这两种多肽。协同红素与26 kDa多肽以1.1协同红素/26 kDa多肽的摩尔比关联。因此，将此多肽指定为TMA协同红素蛋白或TCP。当TMA-MT多肽与纯化的甲基协同红素：CoM甲基转移酶（MT2）一起补充时，可在特定活性下（高达每毫克TMA-MT蛋白600纳摩尔/分钟）发生TMA去甲基化，随后进行CoM甲基化并产生二甲胺。二甲胺或单甲胺均不是底物，活性需要Ti（III）柠檬酸和甲基紫精。TMA-MT可以与MT2的任一同工酶发生相互作用，但对A同工酶亲和力最大。这些结果表明，TCP在TMA依赖性甲烷发酵中起到独特的作用，这种协同红素蛋白被底物甲基化并被MT2的任一同工酶去甲基化，而在TMA生长的细胞中发现的MT2同工酶是TMA：CoM甲基转移反应的主要参与者。
• Clustered Genes Encoding the Methyltransferases of Methanogenesis from Monomethylamine
  作者：Stephen A. Burke、Sam L. Lo、Joseph A. Krzycki

  DOI：10.1128/jb.180.13.3432-3440.1998

  日期：1998.7

  Coenzyme M (CoM) is methylated during methanogenesis from monomethyamine in a reaction catalyzed by three proteins. Using monomethylamine, a 52-kDa polypeptide termed monomethylamine methyltransferase (MMAMT) methylates the corrinoid cofactor bound to a second polypeptide, monomethylamine corrinoid protein (MMCP). Methylated MMCP then serves as a substrate for MT2-A, which methylates CoM. The genes for these

  辅酶 M (CoM) 在由三种蛋白质催化的单甲胺生成甲烷的过程中被甲基化。使用一甲胺，称为一甲胺甲基转移酶 (MMAMT) 的 52 kDa 多肽将与第二个多肽（一甲胺类咕啉蛋白 (MMCP)）结合的类咕啉辅助因子甲基化。然后甲基化的 MMCP 作为 MT2-A 的底物，使 CoM 甲基化。在巴克甲烷八叠球菌 MS 中，这些蛋白质的基因聚集在 6.8 kb 的 DNA 上。编码 MMCP (mtmC) 的基因位于编码 MMAMT (mtmB) 的基因的直接上游。在mtmC上游1.1 kb处发现编码MT2-A（mtbA）的基因，但在mtbA和mtmC之间的基因间区域没有发现明显的开放阅读框。发现 mtbA 的单个单顺反子转录本从翻译起始点开始 76 bp。检测到 2.4 kb 和 4.7 kb 的单独转录本，两者均携带 mtmCB。较大的转录物还编码mtmP，其与阳离子胺通透酶的APC家族同源，因此可能编码甲胺通透酶。在
• Sequence and transcript analysis of a novel Methanosarcina barkeri methyltransferase II homolog and its associated corrinoid protein homologous to methionine synthase
  作者：L Paul、J A Krzycki

  DOI：10.1128/jb.178.22.6599-6607.1996

  日期：1996.11

  The sequence and transcript of the genes encoding a recently discovered coenzyme M methylase in Methanosarcina barkeri were analyzed. This 480-kDa protein is composed of two subunits in equimolar concentrations which bind one corrinoid cofactor per alphabeta dimer. The gene for the alphabeta polypeptide, mtsA, is upstream of that encoding the beta polypeptide, mtsB. The two genes are contiguous and overlap by several nucleotides. A 1.9-kb mRNA species which reacted with probes specific for either mtsA or mtsB was detected. Three possible methanogen consensus BoxA sequences as well as two sets of direct repeats were found upstream of mtsA. The 5' end of the mts transcript was 19 nucleotides upstream of the translational start site of mtsA and was positioned 25 bp from the center of the proximal BoxA sequence. The transcript was most abundant in cells grown to the late log phase on acetate but barely detectable in cells grown on methanol or trimethylamine. The amino acid sequence of MtsB was homologous to the cobalamin-binding fragment of methionine synthase from Escherichia coli and possessed the signature residues involved in binding the corrinoid, including a histidyl residue which ligates cobalt. The sequence of MtsA is homologous to the "A" and "M" isozymes of methylcobamide:coenzyme M methyltransferases (methyltransferase II), indicating that the alpha polypeptide is a new member of the methyltransferase II family of coenzyme M methylases. All three methyltransferase II homolog sequences could be aligned with the sequences of uroporphyrinogen decarboxylase from various sources. The implications of these homologies for the mechanism of corrinoid binding by proteins involved in methylotrophic methanogenesis are discussed.

  分析了在Methanosarcina barkeri中最近发现的辅酶M甲基化酶基因的序列和转录本。这个480kDa的蛋白质由两个亚单位组成，每个亚单位中都结合了一个corrinoid辅因子。编码αβ多肽的基因mtsA位于编码β多肽的基因mtsB的上游。这两个基因是相邻的，并且重叠了几个核苷酸。检测到一种1.9kb的mRNA物种，该物种与特异性探针mtsA或mtsB反应。在mtsA的上游发现了三个可能的甲烷生成菌共识BoxA序列以及两个直接重复的集合。mts转录本的5'末端位于mtsA的翻译起始位点的上游19个核苷酸，并且位于近端BoxA序列中心25 bp处。转录本在以乙酸为基础生长的细胞中最为丰富，但在以甲醇或三甲胺为基础生长的细胞中几乎无法检测到。MtsB的氨基酸序列与大肠杆菌甲硫氨酸合成酶的钴胺素结合片段同源，并具有与结合corrinoid有关的标志性残基，包括一个配位钴的组氨酸残基。MtsA的序列同源于甲基钴胺素：辅酶M甲基转移酶（甲基转移酶II）的“A”和“M”同工酶，表明α多肽是甲基转移酶II家族的辅酶M甲基酶的新成员。所有三个甲基转移酶II同源序列都可以与来自不同来源的卟啉原卟啉原去羧化酶的序列对齐。讨论了这些同源性对于参与甲基烷基化甲烷生成的蛋白质结合corrinoid的机制的影响。
• Function of genetically encoded pyrrolysine in corrinoid-dependent methylamine methyltransferases
  作者：Joseph A Krzycki

  DOI：10.1016/j.cbpa.2004.08.012

  日期：2004.10

  dedicated tRNA, and corresponds to the novel amino acid pyrrolysine in one of the methyltransferases, indicating pyrrolysine to be the 22nd genetically encoded amino acid. Pyrrolysine has the structure of lysine with the (epsilon)N in amide linkage with a pyrroline ring. The reactivity of the electrophilic imine bond is the basis for the proposed function of pyrrolysine in activating and optimally orienting

  由三甲胺，二甲胺或一甲胺的甲烷生成是由一系列依赖于类雌激素的甲基转移酶引发的。编码全长甲基转移酶的非同源基因均具有不终止翻译的框内UAG（琥珀色）密码子。琥珀色密码子由专用的tRNA解码，并对应于一种甲基转移酶中的新型氨基酸吡咯赖氨酸，表明吡咯赖氨酸是第22个遗传编码的氨基酸。吡咯赖氨酸具有赖氨酸的结构，其εN与吡咯啉环具有酰胺键。亲电子亚胺键的反应性是吡咯赖氨酸在活化和最佳定向甲胺以将甲基转移至相关类corrinoid蛋白的钴离子中的功能的基础。