pyridoxine

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡啶及其衍生物
• 英文名称: pyridoxine
• 英文别名: pyridoxal-5’-phosphate；PLP；[5-Hydroxy-4-(hydroxymethyl)-6-methylpyridin-3-yl]methyl phosphate
• 化学式: C₈H₁₀NO₆P
• 分子量: 247.144
• InChiKey: WHOMFKWHIQZTHY-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  -2
• 重原子数：
  16
• 可旋转键数：
  3
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.38
• 拓扑面积：
  126
• 氢给体数：
  2
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  水 、 pyridoxine 生成 H3PO4 、 2-甲基-3-羟基-4,5-二羟甲基吡啶
  参考文献：
  名称：

  Human Pyridoxal Phosphatase

  摘要：

  Pyridoxal phosphatase catalyzes the dephosphorylation of pyridoxal 5'-phosphate (PLP) and pyridoxine 5'-phosphate. A human brain cDNA clone was identified to the PLP phosphatase on the basis of peptide sequences obtained previously. The cDNA predicts a 296-amino acid protein with a calculated M-r of 31698. The open reading frame is encoded by two exons located on human chromosome 22q12.3, and the exon-intron junction contains the GT/AG consensus splice site. In addition, a full-length mouse PLP phosphatase cDNA of 1978 bp was also isolated. Mouse enzyme encodes a protein of 292 amino acids with M-r of 31512, and it is localized on chromosome 15.E1. Human and mouse PLP phosphatase share 93% identity in protein sequence. A BLAST search revealed the existence of putative proteins in organism ranging from bacteria to mammals. Catalytically active human PLP phosphatase was expressed in Escherichia coli, and characteristics of the recombinant enzyme were similar to those of erythrocyte enzyme. The recombinant enzyme displayed K-m and k(cat) values for pyridoxal of 2.5 muM and 1.52 s(-1), respectively. Human PLP phosphatase mRNA is differentially expressed in a tissue-specific manner. A single mRNA transcript of 2.1 kb was detected in all human tissues examined and was highly abundant in the brain. Obtaining the molecular properties for the human PLP phosphatase may provide new direction for investigating metabolic pathway involving vitamin B-6.

  DOI：

  10.1074/jbc.m309619200
• 作为产物：
  描述：

  2-甲基-3-羟基-4,5-二羟甲基吡啶 在 pyridoxal kinase 、 5’-三磷酸腺苷 作用下， 以 aq. buffer 为溶剂， 生成 pyridoxine
  参考文献：
  名称：

  细菌核糖激酶亚家族利用半硫缩醛回收磷酸吡哆醛

  摘要：

  5'-磷酸吡哆醛 (PLP) 是维生素 B6 的活性维生素，在氨基酸和糖代谢的许多方面充当必需的辅助因子。结核分枝杆菌等病原菌的毒力和存活依赖于 PLP，人类的缺陷也与神经系统疾病和炎症有关。虽然 PLP 可以通过细菌和植物中的从头途径合成，但大多数高等生物依赖于磷酸化吡哆醛 (PL) 或其相关维生素、吡哆醇 (PN) 和吡哆胺 (PM) 的补救途径。PL 激酶 (PLK) 是该磷酸化步骤必不可少的，因此对细胞活力至关重要。我们最近在金黄色葡萄球菌中鉴定了一种吡哆醛激酶 (SaPLK) 作为天然产物抗生素 rugulactone (Ru) 的靶点。出奇，Ru 不是在活性位点半胱氨酸上选择性修饰 SaPLK，而是在远程半胱氨酸残基上进行修饰。基于结构和生化研究，我们现在提供了对 PL 磷酸化所必需的前所未有的双 Cys 电荷中继网络的见解。关键组分是盖子区域中的反应性 Cys 110 残基，它与

  DOI：

  10.1021/ja411785r

文献信息

• Identification and Function of the <i>pdxY</i> Gene, Which Encodes a Novel Pyridoxal Kinase Involved in the Salvage Pathway of Pyridoxal 5′-Phosphate Biosynthesis in <i>Escherichia coli</i> K-12
  作者：Yong Yang、Ho-Ching Tiffany Tsui、Tsz-Kwong Man、Malcolm E. Winkler

  DOI：10.1128/jb.180.7.1814-1821.1998

  日期：1998.4

  pdrK encodes a pyridoxine (PN)/pyridoxal (PL)/pyridoxamine (PM) kinase thought to function in the salvage pathway of pyridoxal 5'-phosphate (PLP) coenzyme biosynthesis. The observation that pdxK null mutants still contain PL kinase activity led to the hypothesis that Escherichia coli K-12 contains at least one other B6-vitamer kinase. Here we support this hypothesis by identifying the pdxY gene (formally

  pdrK编码一种吡ido醇（PN）/吡rid醛（PL）/吡rid胺（PM）激酶，该激酶在吡x醛5'-磷酸（PLP）辅酶生物合成的挽救途径中起作用。pdxK null突变体仍然具有PL激酶活性的观察结果导致了这样的假设，即大肠杆菌K-12至少含有一种其他的B6-vitamer激酶。在这里，我们通过在36.92分钟鉴定pdxY基因（正式称为开放阅读框f287b）来支持这一假设，该基因编码一种新型PL激酶。在搜索完整的大肠杆菌基因组时，首先通过与PdxK的同源性鉴定了PdxY。最小的pdxY +克隆过表达PL激酶比活性约10倍。我们将一个omega盒插入pdxY，然后将产生的pdxY :: omegaKan（r）突变插入pdrB突变体的细菌染色体中，在该突变体中从头PLP生物合成被阻断。然后，我们确定了pdxK和pdxY单突变体和双突变体的提取物中的生长特征以及PL和PN激酶特异性活性。值得注意的是，PL和PN不能满足pdxB
• Active site structure and stereospecificity of Escherichia coli pyridoxine-5′-phosphate oxidase
  作者：Martino L di Salvo、Tzu-Ping Ko、Faik N Musayev、Samanta Raboni、Verne Schirch、Martin K Safo

  DOI：10.1006/jmbi.2001.5254

  日期：2002.1

  Pyridoxine-5'-phosphate oxidase catalyzes the oxidation of either the C4' alcohol group or amino group of the two substrates pyridoxine 5'-phosphate and pyridoxamine 5'-phosphate to an aldehyde, forming pyridoxal 5'-phosphate. A hydrogen atom is removed from C4' during the oxidation and a pair of electrons is transferred to tightly bound FMN. A new crystal form of the enzyme in complex with pyridoxal

  吡rid醇-5'-磷酸氧化酶催化两个底物吡ido醇5'-磷酸和吡ido醇胺5'-磷酸的C4'醇基或氨基氧化为醛，形成吡ido醛5'-磷酸。氧化过程中将氢原子从C4'中除去，并将一对电子转移到紧密结合的FMN中。该酶与吡咯醛5'-磷酸盐复合形成的新晶体形式表明，蛋白质的N末端片段在活性位点折叠，从而在催化循环中将配体从溶剂中隔离出来。使用（4'R）-[（3）H] PMP作为底物，氧化成吡ido醛5'-磷酸盐后，几乎100％的放射性标记出现在水中。因此，该酶对于从吡ido胺5′-磷酸的前手性C4′碳原子上除去proR氢原子具有特异性。位点突变体由活性位点上所有与底物C4'上的氧原子或胺基相互作用的残基组成。与底物的磷酸部分相互作用的其他残基被突变。突变体显示亲和力降低，但表现出相当大的催化活性，表明这些残基对于结合很重要，但在催化中的作用较小。Arg197是例外，它对结合和催化均很重要。R197
• Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (<i>PDX3</i>) and the Pyridoxal Kinase (<i>SOS4</i>) Genes Involved in the Vitamin B6 Salvage Pathway
  作者：Eugenia González、David Danehower、Margaret E. Daub

  DOI：10.1104/pp.107.105189

  日期：2007.11.5

  PDX3 and SALT OVERLY SENSITIVE4 (SOS4), encoding pyridoxine/pyridoxamine 5′-phosphate oxidase and pyridoxal kinase, respectively, are the only known genes involved in the salvage pathway of pyridoxal 5′-phosphate in plants. In this study, we determined the phenotype, stress responses, vitamer levels, and regulation of the vitamin B6 pathway genes in Arabidopsis (Arabidopsis thaliana) plants mutant in PDX3 and SOS4. sos4 mutant plants showed a distinct phenotype characterized by chlorosis and reduced plant size, as well as hypersensitivity to sucrose in addition to the previously noted NaCl sensitivity. This mutant had higher levels of pyridoxine, pyridoxamine, and pyridoxal 5′-phosphate than the wild type, reflected in an increase in total vitamin B6 observed through HPLC analysis and yeast bioassay. The sos4 mutant showed increased activity of PDX3 as well as of the B6 de novo pathway enzyme PDX1, correlating with increased total B6 levels. Two independent lines with T-DNA insertions in the promoter region of PDX3 (pdx3-1 and pdx3-2) had decreased PDX3 activity. Both also had decreased activity of PDX1, which correlated with lower levels of total vitamin B6 observed using the yeast bioassay; however, no differences were noted in levels of individual vitamers by HPLC analysis. Both pdx3 mutants showed growth reduction in vitro and in vivo as well as an inability to increase growth under high light conditions. Increased expression of salvage and some of the de novo pathway genes was observed in both the pdx3 and sos4 mutants. In all mutants, increased expression was more dramatic for the salvage pathway genes.

  植物中参与吡哆醛5'-磷酸拯救途径的唯一已知基因是PDX3和SALT OVERLY SENSITIVE4（SOS4），分别编码吡哆醇/吡哆酚5'-磷酸氧化酶和吡哆醛激酶。本研究中，我们确定了PDX3和SOS4突变体的表型、应激反应、维生素B6形式水平和基因调控。sos4突变体植物表现出明显的叶绿素减退和植株大小减小的表型，以及对蔗糖的高敏感性，除了先前已知的对NaCl敏感性之外。该突变体的吡哆醇、吡哆酚胺和吡哆醛5'-磷酸水平高于野生型，通过HPLC分析和酵母生物检测表现为总维生素B6的增加。sos4突变体显示出了PDX3和B6新生途径酶PDX1的活性增加，与总B6水平的增加相关。在PDX3启动子区域中有T-DNA插入的两个独立系(pdx3-1和pdx3-2)的PDX3活性降低。两者的PDX1活性也降低，与使用酵母生物检测观察到的总维生素B6水平的降低相关；但是，HPLC分析没有发现各种维生素形式水平的差异。两个pdx3突变体在离体和体内均表现出生长减缓，并且无法在高光条件下增加生长。在pdx3和sos4突变体中，拯救途径和一些新生途径基因的表达均有所增加。在所有突变体中，拯救途径基因的表达增加更为显著。

• Expression, Purification, and Characterization of RecombinantEscherichia coliPyridoxine 5′-Phosphate Oxidase
  作者：Martino Di Salvo、Emily Yang、Genshi Zhao、Malcolm E. Winkler、Verne Schirch

  DOI：10.1006/prep.1998.0904

  日期：1998.8

  gene from Escherichia coli coding for pyridoxine 5'-phosphate oxidase was transferred to a pET22b vector and expressed in E. coli HMS174(DE3) cells. The soluble overexpressed enzyme was rapidly purified in high yield using two chromatography columns with an overall purification of about 2.8-fold. The purified enzyme contained tightly bound FMN. The enzyme exhibited the same spectral properties and similar

  将先前从大肠杆菌克隆的编码吡ido醇5'-磷酸氧化酶的pdxH基因转移到pET22b载体中，并在大肠杆菌HMS174（DE3）细胞中表达。可溶性过表达的酶使用两个色谱柱以高产率快速纯化，总纯化约为2.8倍。纯化的酶含有紧密结合的FMN。该酶表现出与以前由G.Zhao和MEWinkler（J. Bacteriol。177，883，1995）报道的那些相同的光谱特性和相似的动力学常数，但是与其他研究者报道的特性不同。开发了一种快速制备高产apoPNP Ox的方法。全酶和脱辅酶都是同二聚体。从氨基酸组成确定完全活性的apoPNP Ox的蛋白质的摩尔吸收系数。
• Rv2607 from Mycobacterium tuberculosis Is a Pyridoxine 5′-Phosphate Oxidase with Unusual Substrate Specificity
  作者：Ellene H. Mashalidis、Tathagata Mukherjee、Paweł Śledź、Dijana Matak-Vinković、Helena Boshoff、Chris Abell、Clifton E. Barry

  DOI：10.1371/journal.pone.0027643

  日期：——

  Despite intensive effort, the majority of the annotated Mycobacterium tuberculosis genome consists of genes encoding proteins of unknown or poorly understood function. For example, there are seven conserved hypothetical proteins annotated as homologs of pyridoxine 5′-phosphate oxidase (PNPOx), an enzyme that oxidizes pyridoxine 5′-phosphate (PNP) or pyridoxamine 5′-phosphate (PMP) to form pyridoxal 5′-phosphate (PLP). We have characterized the function of Rv2607 from Mycobacterium tuberculosis H37Rv and shown that it encodes a PNPOx that oxidizes PNP to PLP. The kcat and KM for this reaction were 0.01 s−1 and 360 µM, respectively. Unlike many PNPOx enzymes, Rv2607 does not recognize PMP as a substrate.

  尽管付出了巨大努力，但大部分注释的结核分枝杆菌基因组仍由编码功能未知或了解甚少的蛋白质的基因组成。例如，有七种保守的假定蛋白质被注释为吡哆醇5′-磷酸氧化酶（PNPOx）的同源物，该酶将吡哆醇5′-磷酸（PNP）或吡哆胺5′-磷酸（PMP）氧化为吡哆醛5′-磷酸（PLP）。我们已经鉴定了结核分枝杆菌H37Rv中的Rv2607的功能，并证明它编码一种将PNP氧化为PLP的PNPOx。该反应的kcat和KM分别为0.01 s−1和360 µM。与许多PNPOx酶不同，Rv2607不识别PMP作为底物。