CHM

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: CHM
• 英文别名: 4-hydroxybuta-1,3-diene-1,2,4-tricarboxylic acid
• 化学式: C₇H₆O₇
• 分子量: 202.12
• InChiKey: QWLUKZXOQAQUFQ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.6
• 重原子数：
  14
• 可旋转键数：
  4
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  132
• 氢给体数：
  4
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  CHM 在 4-carboxy-2-hydroxymuconate hydratase 作用下， 以 水 为溶剂， 生成 citroylformic acid
  参考文献：
  名称：

  Structural and Kinetic Characterization of the 4-Carboxy-2-hydroxymuconate Hydratase from the Gallate and Protocatechuate 4,5-Cleavage Pathways of Pseudomonas putida KT2440

  摘要：

  The bacterial catabolism of lignin and its breakdown products is of interest for applications in industrial processing of lignobiomass. The gallate degradation pathway of Pseudomonas putida KT2440 requires a 4-carboxy-2-hydroxymuconate (CHM) hydratase (GalB), which has a 12% sequence identity to a previously identified CHM hydratase (LigJ) from Sphingomonas sp. SYK-6. The structure of GalB was determined and found to be a member of the PIG-L N-acetylglucosamine deacetylase family; GalB is structurally distinct from the amidohydrolase fold of LigJ. LigJ has the same stereospecificity as GalB, providing an example of convergent evolution for catalytic conversion of a common metabolite in bacterial aromatic degradation pathways. Purified GalB contains a bound Zn2+ cofactor; however the enzyme is capable of using Fe2+ and Co2+ with similar efficiency. The general base aspartate in the PIG-L deacetylases is an alanine in GalB; replacement of the alanine with aspartate decreased the GalB catalytic efficiency for CHM by 9.5 x 10(4)-fold, and the variant enzyme did not have any detectable hydrolase activity. Kinetic analyses and pH dependence studies of the wild type and variant enzymes suggested roles for Glu-48 and His-164 in the catalytic mechanism. A comparison with the PIG-L deacetylases led to a proposed mechanism for GalB wherein Glu-48 positions and activates the metal-ligated water for the hydration reaction and His-164 acts as a catalytic acid.

  DOI：

  10.1074/jbc.m115.682054
• 作为产物：
  描述：

  没食子酸 在 4-oxalomesaconate tautomerase 、 gallate dioxygenase 、 氧气 作用下， 以 aq. phosphate buffer 为溶剂， 反应 1.33h， 生成 4-Oxobut-1-ene-1,2,4-tricarboxylic acid 、 CHM
  参考文献：
  名称：

  Structural and Kinetic Characterization of the 4-Carboxy-2-hydroxymuconate Hydratase from the Gallate and Protocatechuate 4,5-Cleavage Pathways of Pseudomonas putida KT2440

  摘要：

  The bacterial catabolism of lignin and its breakdown products is of interest for applications in industrial processing of lignobiomass. The gallate degradation pathway of Pseudomonas putida KT2440 requires a 4-carboxy-2-hydroxymuconate (CHM) hydratase (GalB), which has a 12% sequence identity to a previously identified CHM hydratase (LigJ) from Sphingomonas sp. SYK-6. The structure of GalB was determined and found to be a member of the PIG-L N-acetylglucosamine deacetylase family; GalB is structurally distinct from the amidohydrolase fold of LigJ. LigJ has the same stereospecificity as GalB, providing an example of convergent evolution for catalytic conversion of a common metabolite in bacterial aromatic degradation pathways. Purified GalB contains a bound Zn2+ cofactor; however the enzyme is capable of using Fe2+ and Co2+ with similar efficiency. The general base aspartate in the PIG-L deacetylases is an alanine in GalB; replacement of the alanine with aspartate decreased the GalB catalytic efficiency for CHM by 9.5 x 10(4)-fold, and the variant enzyme did not have any detectable hydrolase activity. Kinetic analyses and pH dependence studies of the wild type and variant enzymes suggested roles for Glu-48 and His-164 in the catalytic mechanism. A comparison with the PIG-L deacetylases led to a proposed mechanism for GalB wherein Glu-48 positions and activates the metal-ligated water for the hydration reaction and His-164 acts as a catalytic acid.

  DOI：

  10.1074/jbc.m115.682054

文献信息

• Structural and Kinetic Characterization of the 4-Carboxy-2-hydroxymuconate Hydratase from the Gallate and Protocatechuate 4,5-Cleavage Pathways of Pseudomonas putida KT2440
  作者：Scott Mazurkewich、Ashley S. Brott、Matthew S. Kimber、Stephen Y.K. Seah

  DOI：10.1074/jbc.m115.682054

  日期：2016.4

  The bacterial catabolism of lignin and its breakdown products is of interest for applications in industrial processing of lignobiomass. The gallate degradation pathway of Pseudomonas putida KT2440 requires a 4-carboxy-2-hydroxymuconate (CHM) hydratase (GalB), which has a 12% sequence identity to a previously identified CHM hydratase (LigJ) from Sphingomonas sp. SYK-6. The structure of GalB was determined and found to be a member of the PIG-L N-acetylglucosamine deacetylase family; GalB is structurally distinct from the amidohydrolase fold of LigJ. LigJ has the same stereospecificity as GalB, providing an example of convergent evolution for catalytic conversion of a common metabolite in bacterial aromatic degradation pathways. Purified GalB contains a bound Zn2+ cofactor; however the enzyme is capable of using Fe2+ and Co2+ with similar efficiency. The general base aspartate in the PIG-L deacetylases is an alanine in GalB; replacement of the alanine with aspartate decreased the GalB catalytic efficiency for CHM by 9.5 x 10(4)-fold, and the variant enzyme did not have any detectable hydrolase activity. Kinetic analyses and pH dependence studies of the wild type and variant enzymes suggested roles for Glu-48 and His-164 in the catalytic mechanism. A comparison with the PIG-L deacetylases led to a proposed mechanism for GalB wherein Glu-48 positions and activates the metal-ligated water for the hydration reaction and His-164 acts as a catalytic acid.