L-idonate

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羟基酸及其衍生物
• 英文名称: L-idonate
• 英文别名: (2R,3S,4R,5S)-2,3,4,5,6-pentahydroxyhexanoate
• 化学式: C6H11O7-
• 分子量: 195.15
• InChiKey: RGHNJXZEOKUKBD-SKNVOMKLSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  -2.7
• 重原子数：
  13
• 可旋转键数：
  4
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  141
• 氢给体数：
  5
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  L-idonate 、 NADP⁺ 生成 2-Dehydro-L-idonate 、 氢(+1)阳离子 、 NADPH(4-)
  参考文献：
  名称：

  The yiaE Gene, Located at 80.1 Minutes on the Escherichia coli Chromosome, Encodes a 2-Ketoaldonate Reductase

  摘要：

  摘要 位于 bisC-cspA 基因间区域的开放阅读框，或位于 大肠杆菌 编码一个假定的 2-羟基酸脱氢酶。 大肠杆菌 基因组测序项目的结果。我们在此报告，该基因的产物 ( yiaE ) 是一种 2-Ketoaldonate 还原酶（2KR）。该基因被克隆并以 C 端 His 标记表达于 大肠杆菌 用金属螯合物亲和层析法纯化了该蛋白。NH 2 -末端氨基酸序列，确定了该基因的翻译起始位点。研究发现，该酶是一种 2KR 催化剂，可催化 2,5-二酮还原为 d -葡萄糖酸还原为 5-酮- d d -葡萄糖酸、2-酮 d -葡萄糖酸（2KDG）转化为 d -葡萄糖酸 2-酮 l -转化为 l -还原酶在 pH 值为 7.5 时活性最佳，NADPH 是首选的电子供体。该还原酶在 pH 值为 7.5 时活性最佳，NADPH 是首选的电子供体。推导出的氨基酸序列与来自 的 2KR .该基因在染色体上的断裂导致 2KR 在大肠杆菌中失去活性。 大肠杆菌。大肠杆菌 W3110 可以在 2KDG 上生长，而缺乏 2KR 活性的突变体则无法在 2KDG 作为碳源的条件下生长。 大肠杆菌 产生的 2KDG 减少。 d -葡萄糖酸产生的 2KDG 减少。 大肠杆菌 葡萄糖酸脱氢酶基因。

  DOI：

  10.1128/jb.180.22.5984-5988.1998

文献信息

• Sequence Analysis of the GntII (Subsidiary) System for Gluconate Metabolism Reveals a Novel Pathway for <scp>l</scp> -Idonic Acid Catabolism in <i>Escherichia coli</i>
  作者：Christoph Bausch、Norbert Peekhaus、Cristina Utz、Tessa Blais、Elizabeth Murray、Todd Lowary、Tyrrell Conway

  DOI：10.1128/jb.180.14.3704-3710.1998

  日期：1998.7.15

  The presence of two systems in Escherichia coli for gluconate transport and phosphorylation is puzzling. The main system, GntI, is well characterized, while the subsidiary system, GntII, is poorly understood. Genomic sequence analysis of the region known to contain genes of the GntII system led to a hypothesis which was tested biochemically and confirmed: the GntII system encodes a pathway for catabolism of l -idonic acid in which d -gluconate is an intermediate. The genes have been named accordingly: the idnK gene, encoding a thermosensitive gluconate kinase, is monocistronic and transcribed divergently from the idnD-idnO-idnT-idnR operon, which encodes l -idonate 5-dehydrogenase, 5-keto- d -gluconate 5-reductase, an l -idonate transporter, and an l -idonate regulatory protein, respectively. The metabolic sequence is as follows: IdnT allows uptake of l -idonate; IdnD catalyzes a reversible oxidation of l -idonate to form 5-ketogluconate; IdnO catalyzes a reversible reduction of 5-ketogluconate to form d -gluconate; IdnK catalyzes an ATP-dependent phosphorylation of d -gluconate to form 6-phosphogluconate, which is metabolized further via the Entner-Doudoroff pathway; and IdnR appears to act as a positive regulator of the IdnR regulon, with l -idonate or 5-ketogluconate serving as the true inducer of the pathway. The l -idonate 5-dehydrogenase and 5-keto- d -gluconate 5-reductase reactions were characterized both chemically and biochemically by using crude cell extracts, and it was firmly established that these two enzymes allow for the redox-coupled interconversion of l -idonate and d -gluconate via the intermediate 5-ketogluconate. E. coli K-12 strains are able to utilize l -idonate as the sole carbon and energy source, and as predicted, the ability of idnD , idnK , idnR , and edd mutants to grow on l -idonate is altered.

  摘要 大肠杆菌中存在两个系统 大肠杆菌 葡萄糖酸盐转运和磷酸化的两个系统令人费解。主系统 GntI 的特征十分明确，而附属系统 GntII 却鲜为人知。对已知含有 GntII 系统基因的区域进行基因组序列分析后，我们提出了一个假设，并对该假设进行了生物化学测试和证实：GntII 系统编码的是一条葡萄糖酸盐的分解途径。 l -酸的代谢途径，其中 d -葡萄糖酸是中间产物。这些基因被相应地命名为 idnK 基因编码一种热敏葡萄糖酸激酶，是单序列基因，与 idnD-idnO-idnT-idnR 操作子，该操作子编码 l -酮酸 5-脱氢酶、5-酮- d -葡萄糖酸 5-还原酶、一个 l -亚酮酸转运体和 l -调节蛋白。代谢顺序如下：IdnT 允许吸收 l -idonate 的可逆氧化；IdnD 催化 l l -生成 5-酮基葡萄糖酸；IdnO 催化 5-酮基葡萄糖酸的可逆还原生成 d -葡萄糖酸；IdnK 催化依赖于 ATP 的 d -葡萄糖酸盐形成 6-磷酸葡萄糖酸盐，后者通过 Entner-Doudoroff 途径进一步代谢；IdnR 似乎充当 IdnR 调节子的正向调节器，与 l -酮或 5-酮基葡萄糖酸作为该途径的真正诱导剂。l l 5-idonate 5-脱氢酶和 5-Keto- d -葡萄糖酸 5-还原酶反应的化学和生物化学特征。 l -和 d -葡萄糖酸通过中间体 5-酮基葡萄糖酸进行氧化还原耦合相互转化。 大肠杆菌 K-12 菌株能够利用 l -葡萄糖酸作为唯一的碳源和能量来源。 idnD , idnK , idnR 和 edd 突变体在 l -发生改变。
• <scp>l</scp> -Tartaric acid synthesis from vitamin C in higher plants
  作者：Seth DeBolt、Douglas R. Cook、Christopher M. Ford

  DOI：10.1073/pnas.0510864103

  日期：2006.4.4

  from genes expressed at developmental times and in tissues appropriate for L-tartaric acid biosynthesis in grape berries. Enzymological analyses of one candidate confirmed its activity in the proposed rate-limiting step of the direct pathway from vitamin C to tartaric acid in higher plants. Surveying organic acid content in Vitis and related genera, we have identified a non-tartrate-forming species

  L-酒石酸（自然界中最常见的形式）及其与维生素C的分解代谢联系，其生物合成途径仍然是植物科学家面临的挑战。维生素C和L-酒石酸是具有人体固有价值的植物代谢产物。与发育过程中的大多数水果相反，葡萄会积累L-酒石酸，而L-酒石酸会在整个成熟过程中保留在浆果中。浆果的味道，葡萄酒的感官特性和陈年潜力与水果中存在的L-酒石酸水平以及葡萄酒酿造过程中添加的酒石酸水平密切相关。阐明了葡萄科中L-酒石酸与维生素C分解代谢相关的反应表明，它们是通过L-碘酸的氧化而进行的，这是该途径中的限速步骤。在这里，我们报告转录物和代谢物谱的使用，以从发育时间和组织中表达的基因中识别候选cDNA，这些基因适合葡萄浆果中L-酒石酸的生物合成。对一种候选物的酶学分析证实了其在高等植物中从维生素C到酒石酸的直接途径的拟议限速步骤中的活性。调查葡萄和相关属中的有机酸含量，我们已经确定了该基因缺失的非酒石酸形成物种。该物种积累的
• The <i>yiaE</i> Gene, Located at 80.1 Minutes on the <i>Escherichia coli</i> Chromosome, Encodes a 2-Ketoaldonate Reductase
  作者：Do-Young Yum、Bong-Yong Lee、Dae-Hyum Hahm、Jae-Gu Pan

  DOI：10.1128/jb.180.22.5984-5988.1998

  日期：1998.11.15

  An open reading frame located in the bisC-cspA intergenic region, or at 80.1 min on the Escherichia coli chromosome, encodes a hypothetical 2-hydroxyacid dehydrogenase, which was identified as a result of the E. coli Genome Sequencing Project. We report here that the product of the gene ( yiaE ) is a 2-ketoaldonate reductase (2KR). The gene was cloned and expressed with a C-terminal His tag in E. coli , and the protein was purified by metal-chelate affinity chromatography. The determination of the NH ₂ -terminal amino acid sequence of the protein defined the translational start site of this gene. The enzyme was found to be a 2KR catalyzing the reduction of 2,5-diketo- d -gluconate to 5-keto- d -gluconate, 2-keto- d -gluconate (2KDG) to d -gluconate, 2-keto- l -gulonate to l -idonate. The reductase was optimally active at pH 7.5, with NADPH as a preferred electron donor. The deduced amino acid sequence showed 69.4% identity with that of 2KR from Erwinia herbicola . Disruption of this gene on the chromosome resulted in the loss of 2KR activity in E. coli. E. coli W3110 was found to grow on 2KDG, whereas the mutant deficient in 2KR activity was unable to grow on 2KDG as the carbon source, suggesting that 2KR is responsible for the catabolism of 2KDG in E. coli and the diminishment of produced 2KDG from d -gluconate in the cultivation of E. coli harboring a cloned gluconate dehydrogenase gene.

  摘要 位于 bisC-cspA 基因间区域的开放阅读框，或位于 大肠杆菌 编码一个假定的 2-羟基酸脱氢酶。 大肠杆菌 基因组测序项目的结果。我们在此报告，该基因的产物 ( yiaE ) 是一种 2-Ketoaldonate 还原酶（2KR）。该基因被克隆并以 C 端 His 标记表达于 大肠杆菌 用金属螯合物亲和层析法纯化了该蛋白。NH 2 -末端氨基酸序列，确定了该基因的翻译起始位点。研究发现，该酶是一种 2KR 催化剂，可催化 2,5-二酮还原为 d -葡萄糖酸还原为 5-酮- d d -葡萄糖酸、2-酮 d -葡萄糖酸（2KDG）转化为 d -葡萄糖酸 2-酮 l -转化为 l -还原酶在 pH 值为 7.5 时活性最佳，NADPH 是首选的电子供体。该还原酶在 pH 值为 7.5 时活性最佳，NADPH 是首选的电子供体。推导出的氨基酸序列与来自 的 2KR .该基因在染色体上的断裂导致 2KR 在大肠杆菌中失去活性。 大肠杆菌。大肠杆菌 W3110 可以在 2KDG 上生长，而缺乏 2KR 活性的突变体则无法在 2KDG 作为碳源的条件下生长。 大肠杆菌 产生的 2KDG 减少。 d -葡萄糖酸产生的 2KDG 减少。 大肠杆菌 葡萄糖酸脱氢酶基因。
• An aldo-keto reductase with 2-keto-l-gulonate reductase activity functions in l-tartaric acid biosynthesis from vitamin C in Vitis vinifera
  作者：Yong Jia、Crista A. Burbidge、Crystal Sweetman、Emi Schutz、Kathy Soole、Colin Jenkins、Robert D. Hancock、John B. Bruning、Christopher M. Ford

  DOI：10.1074/jbc.ra119.010196

  日期：2019.11

  Tartaric acid has high economic value as an antioxidant and flavorant in food and wine industries. l-Tartaric acid biosynthesis in wine grape (Vitis vinifera) uses ascorbic acid (vitamin C) as precursor, representing an unusual metabolic fate for ascorbic acid degradation. Reduction of the ascorbate breakdown product 2-keto-l-gulonic acid to l-idonic acid constitutes a critical step in this l-tartaric acid biosynthetic pathway. However, the underlying enzymatic mechanisms remain obscure. Here, we identified a V. vinifera aldo-keto reductase, Vv2KGR, with 2-keto-l-gulonic acid reductase activity. Vv2KGR belongs to the d-isomer?specific 2-hydroxyacid dehydrogenase superfamily and displayed the highest similarity to the hydroxyl pyruvate reductase isoform 2 in Arabidopsis thaliana. Enzymatic analyses revealed that Vv2KGR efficiently reduces 2-keto-l-gulonic acid to l-idonic acid and uses NADPH as preferred coenzyme. Moreover, Vv2KGR exhibited broad substrate specificity toward glyoxylate, pyruvate, and hydroxypyruvate, having the highest catalytic efficiency for glyoxylate. We further determined the X-ray crystal structure of Vv2KGR at 1.58 ? resolution. Comparison of the Vv2KGR structure with those of d-isomer?specific 2-hydroxyacid dehydrogenases from animals and microorganisms revealed several unique structural features of this plant hydroxyl pyruvate reductase. Substrate structural analysis indicated that Vv2KGR uses two modes (A and B) to bind different substrates. 2-Keto-l-gulonic acid displayed the lowest predicted free-energy binding to Vv2KGR among all docked substrates. Hence, we propose that Vv2KGR functions in l-tartaric acid biosynthesis. To the best of our knowledge, this is the first report of a d-isomer?specific 2-hydroxyacid dehydrogenase that reduces 2-keto-l-gulonic acid to l-idonic acid in plants.