acetopyruvate | 16709-26-5

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 酮酸及其衍生物
• 英文名称: acetopyruvate
• 英文别名: Acetylpyruvate；2,4-dioxopentanoate
• CAS: 16709-26-5
• 化学式: C₅H₅O₄
• 分子量: 129.092
• InChiKey: UNRQTHVKJQUDDF-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  0.2
• 重原子数：
  9
• 可旋转键数：
  2
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  74.3
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  acetopyruvate 、 水 生成 乙酸盐 、 氢(+1)阳离子 、 piruvate
  参考文献：
  名称：

  Davey J.F.; Ribbons D.W., J Biol Chem, 1975, 0021-9258, 3826-30

  摘要：

  DOI：
• 作为产物：
  描述：

  2-oxo-3-pentynoate 在 tautomerase superfamily N₁ 作用下， 以 氘代二甲亚砜 、 aq. phosphate buffer 为溶剂， 生成 acetopyruvate
  参考文献：
  名称：

  Kinetic and Structural Analysis of Two Linkers in the Tautomerase Superfamily: Analysis and Implications

  摘要：

  双烯酮异构酶超家族（TSF）是一组共享简单β–α–β结构支架的酶和蛋白质。大多数成员由单个核心β–α–β基序或两个连续融合的β–α–β基序构成，其中N-末端脯氨酸（Pro-1）作为催化残基发挥关键而独特的作用。累计证据表明，在TSF的进化过程中发生了基因融合事件，随后对新融合基因进行了复制，从而导致了今天所见的活性多样化。对TSF的序列相似性网络（SSN）分析识别出几种连接蛋白（“连接器”），它们的相似性将这些当代蛋白质的子群联系起来，这可能为新活性出现时伴随的结构–功能关系变化提供线索。在SSN中识别出一对先前未表征的连接器（指定为N1和N2），它们连接了4-草酰基氯烯烃异构酶（4-OT）和顺式-3-氯丙烯酸脱卤酶（cis-CaaD）子群。N1位于cis-CaaD子群中，具有顺式-CaaD活性所需的全面活性位点残基，而N2位于4-OT子群中，缺少用于典型4-OT活性的重要精氨酸（Arg-39）。动力学表征和核磁共振分析显示，N1的活性与cis-CaaD子群中的其他已表征成员相似，且效率各不相同。N2是一个适度的4-OT，但在使用炔烃和乙炔化合物时显示出增强的水合酶活性，这可能与Arg-8和Arg-11的存在有关。晶体学分析为这些观察提供了结构背景。

  DOI：

  10.1021/acs.biochem.1c00220

文献信息

• Characterization of a Newly Identified Mycobacterial Tautomerase with Promiscuous Dehalogenase and Hydratase Activities Reveals a Functional Link to a Recently Diverged <i>cis</i>-3-Chloroacrylic Acid Dehalogenase
  作者：Bert-Jan Baas、Ellen Zandvoort、Anna A. Wasiel、Wim J. Quax、Gerrit J. Poelarends

  DOI：10.1021/bi200071k

  日期：2011.4.12

  The enzyme cis-3-chloroacrylic acid dehalogenase (cis-CaaD) is found in a bacterial pathway that degrades a synthetic nematocide, cis-1,3-dichloropropene, introduced in the 20th century. The previously determined crystal structure of cis-CaaD and its promiscuous phenylpyruvate tautomerase (PPT) activity link this dehalogenase to the tautomerase superfamily, a group of homologous proteins that are characterized by a catalytic amino-terminal proline and a beta-alpha-beta structural fold. The low-level PPT activity of cis-CaaD, which may be a vestige of the function of its progenitor, prompted us to search the databases for a homologue of cis-CaaD that was annotated as a putative tautomerase and test both its PPT and cis-CaaD activity. We identified a mycobacterial cis-CaaD homologue (designated MsCCH2) that shares key sequence and active site features with cis-CaaD. Kinetic and H-1 NMR spectroscopic studies show that MsCCH2 functions as an efficient PPT and exhibits low-level promiscuous dehalogenase activity, processing both cis- and trans-3-chloroacrylic acid. To further probe the active site of MsCCH2, the enzyme was incubated with 2-oxo-3-pentynoate (2-OP). At pH 8.5, MsCCH2 is inactivated by 2-OP due to the covalent modification of Pro-1, suggesting that Pro-1 functions as a nucleophile at pH 8.5 and attacks 2-OP in a Michael-type reaction. At pH 6.5, however, MsCCH2 exhibits hydratase activity and converts 2-013 to acetopyruvate, which implies that Pro-1 is cationic at pH 6.5 and not functioning as a nucleophile. At pH 7.5, the hydratase and inactivation reactions occur simultaneously. From these results, it can be inferred that Pro-1 of MsCCH2 has a pK(a) value that lies in between that of a typical tautomerase (pK(a) of Pro-I similar to 6) and that of cis-CaaD (pK(a) of Pro-I similar to 9). The shared activities and structural features, coupled with the intermediate pK(a) of Pro-1, suggest that MsCCH2 could be characteristic of an evolutionary intermediate along the past route for the divergence of cis-CaaD from an unknown superfamily tautomerase. This makes MsCCH2 an ideal candidate for laboratory evolution of its promiscuous dehalogenase activity, which could identify additional features necessary for a fully active cis-CaaD. Such results will provide insight into pathways that could lead to the rapid divergent evolution of an efficient cis-CaaD enzyme.