aspartyl indole-3-acetic acid | 1254209-01-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吲哚及其衍生物
• 英文名称: aspartyl indole-3-acetic acid
• CAS: 1254209-01-2
• 化学式: C₁₄H₁₄N₂O₆
• 分子量: 306.275
• InChiKey: ULWFXJSWHDTJBQ-NSHDSACASA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.69
• 重原子数：
  22.0
• 可旋转键数：
  7.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.21
• 拓扑面积：
  128.72
• 氢给体数：
  4.0
• 氢受体数：
  5.0

反应信息

• 作为产物：
  描述：

  3-吲哚乙酸 、 aspartic acid anion II 在 磷烯醇丙酮酸 、 rabbit muscle lactate dehydrogenase 、 rabbit muscle pyruvate kinase 、 Oryza sativa indole-3-acetic acid-amido synthetase GH₃-8 hexahistidine-tagged protein 、 rabbit muscle myokinase 、 5’-三磷酸腺苷 、 还原型辅酶Ⅰ 、 magnesium chloride 、 Cleland's reagent 作用下， 生成 aspartyl indole-3-acetic acid
  参考文献：
  名称：

  Kinetic Basis for the Conjugation of Auxin by a GH3 Family Indole-acetic Acid-Amido Synthetase

  摘要：

  The GH3 family of acyl-acid-amido synthetases catalyze the ATP-dependent formation of amino acid conjugates to modulate levels of active plant hormones, including auxins and jasmonates. Initial biochemical studies of various GH3s show that these enzymes group into three families based on sequence relationships and acyl-acid substrate preference (I, jasmonate-conjugating; II, auxin- and salicylic acid-conjugating; III, benzoate-conjugating); however, little is known about the kinetic and chemical mechanisms of these enzymes. Here we use GH3-8 from Oryza sativa (rice; OsGH3-8), which functions as an indoleacetic acid (IAA)-amido synthetase, for detailed mechanistic studies. Steady-state kinetic analysis shows that the OsGH3-8 requires either Mg2+ or Mn2+ for maximal activity and is specific for aspartate but accepts asparagine as a substrate with a 45-fold decrease in catalytic efficiency and accepts other auxin analogs, including phenylacetic acid, indole butyric acid, and naphthaleneacetic acid, as acyl-acid substrates with 1.4-9-fold reductions in k(cat)/K-m relative to IAA. Initial velocity and product inhibition studies indicate that the enzyme uses a Bi Uni Uni Bi Ping Pong reaction sequence. In the first half-reaction, ATP binds first followed by IAA. Next, formation of an adenylated IAA intermediate results in release of pyrophosphate. The second half-reaction begins with binding of aspartate, which reacts with the adenylated intermediate to release IAA-Asp and AMP. Formation of a catalytically competent adenylated-IAA reaction intermediate was confirmed by mass spectrometry. These mechanistic studies provide insight on the reaction catalyzed by the GH3 family of enzymes to modulate plant hormone action.

  DOI：

  10.1074/jbc.m110.146431