(R)-2-(4-Chloro-2-methylphenoxy)propanoate

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: (R)-2-(4-Chloro-2-methylphenoxy)propanoate
• 英文别名: (2R)-2-(4-chloro-2-methylphenoxy)propanoate
• 化学式: C10H10ClO3-
• 分子量: 213.64
• InChiKey: WNTGYJSOUMFZEP-SSDOTTSWSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  3.8
• 重原子数：
  14
• 可旋转键数：
  2
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.3
• 拓扑面积：
  49.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  (R)-2-(4-Chloro-2-methylphenoxy)propanoate 、 2-氧代-戊二酸离子(2-) 、 氧气 生成 4-氯-2-甲基苯酚 、 二氧化碳 、 piruvate 、 琥珀酸根
  参考文献：
  名称：

  Purification and Characterization of Two Enantioselective α-Ketoglutarate-Dependent Dioxygenases, RdpA and SdpA, fromSphingomonas herbicidovoransMH

  摘要：

  摘要α-酮戊二酸依赖性（R）-二氯丙二加氧酶（RdpA）和α-酮戊二酸依赖性（S）-二氯丙二加氧酶（SdpA）参与了Sphingomonas herbicidovoransMH中苯氧烷酸类除草剂的降解。RdpA 和 SdpA 属于α-酮戊二酸依赖性二氧合酶的第二亚群，共享特异性基序 HXDX24TX131HX10R。氨基酸 His-111、Asp-113 和 His-270 以及氨基酸 His-102、Asp-104 和 His 257 构成了 2-His-1-羧酸面三元组，并被预测分别参与了 RdpA 和 SdpA 的铁结合。RdpA 只转化麦考酚酸[2-(4-氯-2-甲基苯氧基)丙酸]和二氯丙酸[2-(2,4-二氯苯氧基)丙酸]的 (R) 对映异构体，而 SdpA 对 (S) 对映异构体具有特异性。对 RdpA 而言，(R)-mecoprop 的表观 Km 值为 99 μM，(R)-dichlorprop 为 164 μM，α-ketoglutarate 为 3 μM；对 SdpA 而言，(S)-mecoprop 为 132 μM，(S)-dichlorprop 为 495 μM，α-ketoglutarate 为 20 μM。两种酶对氧气的表观 Km 值都很高；SdpA 为 159 μM，RdpA 为 230 μM。这两种酶的共底物特异性都很窄；只有 2-oxoadipate 能够取代 α-酮戊二酸，而且速率大大降低。酶的活性需要亚铁，其他二价阳离子无法替代。尽管生长实验结果表明，菌株 MH 中含有一种特异的 2,4-二氯苯氧乙酸转化酶 tfdA-、tfdAα-，但在使用异源杂交和 PCR 的筛选分析中，并未发现类似于 orcadAB 的基因。

  DOI：

  10.1128/aem.02758-05

文献信息

• Structural basis for the enantiospecificities of<i>R</i>- and<i>S-</i>specific phenoxypropionate/α-ketoglutarate dioxygenases
  作者：Tina A. Müller、Maria I. Zavodszky、Michael Feig、Leslie A. Kuhn、Robert P. Hausinger

  DOI：10.1110/ps.052059406

  日期：2006.6

  Abstract(R)‐ and (S)‐dichlorprop/α‐ketoglutarate dioxygenases (RdpA and SdpA) catalyze the oxidative cleavage of 2‐(2,4‐dichlorophenoxy)propanoic acid (dichlorprop) and 2‐(4‐chloro‐2‐methyl‐phenoxy)propanoic acid (mecoprop) to form pyruvate plus the corresponding phenol concurrent with the conversion of α‐ketoglutarate (αKG) to succinate plus CO2. RdpA and SdpA are strictly enantiospecific, converting only the (R) or the (S) enantiomer, respectively. Homology models were generated for both enzymes on the basis of the structure of the related enzyme TauD (PDB code 1OS7). Docking was used to predict the orientation of the appropriate mecoprop enantiomer in each protein, and the predictions were tested by characterizing the activities of site‐directed variants of the enzymes. Mutant proteins that changed at residues predicted to interact with (R)‐ or (S)‐mecoprop exhibited significantly reduced activity, often accompanied by increased Km values, consistent with roles for these residues in substrate binding. Four of the designed SdpA variants were (slightly) active with (R)‐mecoprop. The results of the kinetic investigations are consistent with the identification of key interactions in the structural models and demonstrate that enantiospecificity is coordinated by the interactions of a number of residues in RdpA and SdpA. Most significantly, residues Phe171 in RdpA and Glu69 in SdpA apparently act by hindering the binding of the wrong enantiomer more than the correct one, as judged by the observed decreases in Km when these side chains are replaced by Ala.
• The two enantiospecific dichlorprop/α-ketoglutarate-dioxygenases from Delftia acidovorans MC1 – protein and sequence data of RdpA and SdpA
  作者：Anne Westendorf、Dirk Benndorf、Roland H. Müller、Wolfgang Babel

  DOI：10.1078/0944-5013-00164

  日期：——

  Two alpha-ketoglutarate-dependent dioxygenases carrying enantiospecific activity for the etherolytic cleavage of racemic phenoxypropionate herbicides [(RS)-2-(2,4-dichlorophenoxy)propionate and (RS)-2-(4-chloro-2-methylphenoxy)propionate] from Delftia acidovorans MC1 were characterized with respect to protein and sequence data. The (S)-phenoxy-propionate/alpha-ketoglutarate-dioxygenase (SdpA) appeared as a monomeric enzyme with a molecular weight of 32 kDa in the presence of SDS. N-terminal sequences revealed relationship to alpha-ketoglutarate-dependent taurine dioxygenase (TauD) and to 2,4-dichlorophenoxyacetate/alpha-ketoglutarate-dioxygenase (TfdA). The (R)-phenoxypropionate/alpha-ketoglutarate-dioxygenase (RdpA) referred to 36 kDa in the presence of SDS and to 108 kDa under native conditions. Internal sequences of fragments obtained after digestion made evident relationship to TfdA and TauD. Two-dimensional electrophoretic separation resulted in the resolution of up to 3 individual spots with almost identical molecular weights but different isoelectric points with both RdpA and SdpA. The structural differences of these isoenzyme forms are not yet clear.