(4S,5R)-4,5,6-trihydroxy-2-iminohexanoic acid

• 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: (4S,5R)-4,5,6-trihydroxy-2-iminohexanoic acid
• 化学式: C₆H₁₁NO₅
• 分子量: 177.16
• InChiKey: LHJBIZHHMPOXFL-CRCLSJGQSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -2.2
• 重原子数：
  12
• 可旋转键数：
  5
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  122
• 氢给体数：
  5
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  (4S,5R)-4,5,6-trihydroxy-2-iminohexanoic acid 、 水 生成 (4S,5R)-D-2-keto-3-deoxy-gluconate 、 铵
  参考文献：
  名称：

  D-Glucosaminate Dehydratase from Agrobacterium radiobacter. Physicochemical and Enzymological Properties

  摘要：

  研究了 D-氨基葡萄糖脱水酶 EEC 4.2.1.26]的细菌分布情况，发现辐射农杆菌（IAM 1526）的酶活性最高。在甘油-尿素培养基中，D-氨基葡萄糖、D-半乳糖胺和 D-氨基葡萄糖可诱导形成该酶，但 D-甘露糖胺不能诱导形成该酶。通过超速离心法，从葡萄糖胺-甘油-尿素培养基中生长的细胞中纯化出的酶是均匀的。用沉降平衡法测定其分子量约为 66 000，用凝胶渗透色谱低角度光散射法测定其分子量约为 72 800。最适 pH 值为 8.3-9.0。该酶可催化 D-氨基葡萄糖酸（相对活性：100，Km：2.8 mM）、D-半乳糖氨酸（31.5，5.0 mM）、D-甘露氨酸（17.5，29 mM）、D-苏氨酸（5.1，4.8 mM）、D-丝氨酸（3.2，0.026 mM）和 L-丝氨酸（1.1，ND）脱水，但不能催化 L-苏氨酸。反向反应不会发生。该酶受 5'-磷酸吡哆醛酶的典型抑制剂（如 L-青霉胺）以及羰基试剂、硫醇试剂、二价金属和几种 D-氨基酸和 D-氨基糖的抑制。

  DOI：

  10.1093/oxfordjournals.jbchem.a133686
• 作为产物：
  描述：

  (Z,4S,5R)-2-azaniumyl-4,5,6-trihydroxyhex-2-enoate 生成 (4S,5R)-4,5,6-trihydroxy-2-iminohexanoic acid
  参考文献：
  名称：

  D-Glucosaminate Dehydratase from Agrobacterium radiobacter. Physicochemical and Enzymological Properties

  摘要：

  研究了 D-氨基葡萄糖脱水酶 EEC 4.2.1.26]的细菌分布情况，发现辐射农杆菌（IAM 1526）的酶活性最高。在甘油-尿素培养基中，D-氨基葡萄糖、D-半乳糖胺和 D-氨基葡萄糖可诱导形成该酶，但 D-甘露糖胺不能诱导形成该酶。通过超速离心法，从葡萄糖胺-甘油-尿素培养基中生长的细胞中纯化出的酶是均匀的。用沉降平衡法测定其分子量约为 66 000，用凝胶渗透色谱低角度光散射法测定其分子量约为 72 800。最适 pH 值为 8.3-9.0。该酶可催化 D-氨基葡萄糖酸（相对活性：100，Km：2.8 mM）、D-半乳糖氨酸（31.5，5.0 mM）、D-甘露氨酸（17.5，29 mM）、D-苏氨酸（5.1，4.8 mM）、D-丝氨酸（3.2，0.026 mM）和 L-丝氨酸（1.1，ND）脱水，但不能催化 L-苏氨酸。反向反应不会发生。该酶受 5'-磷酸吡哆醛酶的典型抑制剂（如 L-青霉胺）以及羰基试剂、硫醇试剂、二价金属和几种 D-氨基酸和 D-氨基糖的抑制。

  DOI：

  10.1093/oxfordjournals.jbchem.a133686

文献信息

• <scp>D</scp>-Glucosaminate Aldolase Activity of<scp>D</scp>-Glucosaminate Dehydratase from<i>Pseudomonas fluorescens</i>and Its Requirement for Mn²⁺Ion
  作者：Ryoko Iwamoto、Hisae Taniki、Junko Koishi、Satomi Nakura

  DOI：10.1271/bbb.59.408

  日期：1995.1

  When D-glucosaminate dehydratase (GADH) was incubated with D-glucosaminate (GlcNA) in veronal buffer (VB; 0.01 M, pH 8.0), GlcNA was converted stoichiometrically to glyceraldehyde, pyruvate, and ammonia (aldolase reaction A). This reaction occurred in addition to the dehydratase reaction (conversion of GlcNA to 2-keto-3-deoxy-o-gluconate and ammonia: α,β-elimination reaction, B). The ratio of the activities (A:B) was about 1:4. However, in potassium phosphate buffer (KPB; 0.04 M, pH 8.0), the aldolase reaction was inhibited to 3–4% of that in VB, and also inhibited by various derivatives of glycerol, in particular, glycerol-3-phosphate (glycerol-3-P) and glyceraldehyde-3-phosphate (glyceraldehyde-3-P) in VB. The native enzyme was inhibited by incubation with 0.1 M EDTA, and the activity was restored by incubation of the EDTA-treated enzyme with (Mn2+ + pyridoxal 5′-phosphate (PLP)). When the EDTA-treated enzyme was incubated with (Mn2+ + PLP + glycerol-3-P), the activity of reaction B increased to 131% but that of reaction A decreased to 21%. These results suggested that Mn2+, PLP, and the phosphate group of glycerol-3-P are involved in formation of the active enzyme. In the case of the aldolase reaction, Mn2+ ion, which might be essential for the reaction, is chelated by the phosphate group of glycerol-3-P with resultant inhibition of the aldolase reaction.

  当D-氨基葡萄糖酸脱氢酶（GADH）与D-氨基葡萄糖酸（GlcNA）在维罗纳缓冲液（VB；0.01 M，pH 8.0）中孵育时，GlcNA按化学计量转化为甘油醛、丙酮酸和氨（醛缩酶反应A）。除了脱氢酶反应（将GlcNA转化为2-酮-3-脱氧-o-葡萄糖酸和氨：α，β-消除反应，B）外，还会发生这种反应。活性比（A：B）约为1：4。然而，在磷酸钾缓冲液（KPB；0.04 M，pH 8.0）中，醛缩酶反应被抑制至VB反应的3-4%，并且被甘油的各种衍生物抑制，特别是VB中的甘油-3-磷酸（甘油-3-P）和甘油醛-3-磷酸（甘油醛-3-P）。天然酶在0.1 M EDTA中孵育会被抑制，而经EDTA处理的酶在（Mn2+ +吡哆醛5′-磷酸（PLP））中孵育后活性会恢复。当经EDTA处理的酶在（Mn2+ + PLP +甘油-3-P）中孵育时，反应B的活性会增加到131%，但反应A的
• The d-glucosaminate dehydratase alpha-subunit from Pseudomonas fluorescens exhibits thioredoxin reductase activity
  作者：Ryoko Iwamoto、Chie Amano、Kenji Ikehara、Naomi Ushida

  DOI：10.1016/s1570-9639(03)00079-7

  日期：2003.4

  The complete amino acid sequence of the D-glucosaminate dehydratase (GADH) alpha-subunit from Pseudomonas fluorescens was determined by PCR using genomic DNA from P fluorescens as a template. The alpha-subunit comprises 320 amino acids and has a molecular mass of about 33.9 kDa. The primary structure of the alpha-subunit demonstrates a high similarity to the structures of thioredoxin reductase (TrxR) from many prokaryotes, especially Pseudomonas aeruginosa (identity 85%, positive 91%), Vibrio cholerae (identity 73%, positive 85%), and Escherichia coli (identity 71%, positive 83%). The purified glucosaminate dehydratase alpha(2)-enzyme exhibited NADPH-dependent TrxR activity, while TrxR from E. coli showed pyridoxal 5'-phosphate (PLP)-dependent GADH activity. The TrxR from E. coli suggests that there are three cofactor binding sites, FAD, NADPH, and PLP in the enzyme and that TrxR catalyzes the FAD- and NADPH-dependent oxidation-reduction reaction and the PLP-dependent alpha,beta-elimination reaction. (C) 2003 Elsevier Science B.V. All rights reserved.