2-(5-methoxy-1H-indol-3-yl)ethylazanium

• 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: 2-(5-methoxy-1H-indol-3-yl)ethylazanium
• 化学式: C11H15N2O+
• 分子量: 191.25
• InChiKey: JTEJPPKMYBDEMY-UHFFFAOYSA-O

计算性质

• 辛醇/水分配系数(LogP)：
  0.5
• 重原子数：
  14
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.27
• 拓扑面积：
  52.7
• 氢给体数：
  2
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  2-(5-methoxy-1H-indol-3-yl)ethylazanium 、 (2R)-N-[3-(2-acetylsulfanylethylimino)-3-oxidopropyl]-4-[[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-4-hydroxy-3-phosphonatooxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-hydroxyphosphoryl]oxy-2-hydroxy-3,3-dimethylbutanimidate 生成 coenzyme A 、 氢(+1)阳离子 、 褪黑素
  参考文献：
  名称：

  Molecular cloning of rice serotoninN-acetyltransferase, the penultimate gene in plant melatonin biosynthesis

  摘要：

  AbstractBecause of the absence of an arylalkylamine N‐acetyltransferase (AANAT) homolog in the plant genome, the proposal was made that a GCN5‐related N‐acetyltransferase superfamily gene (GNAT) could be substituted for AANAT. To clone rice serotonin N‐acetyltransferase (SNAT), we expressed 31 rice GNAT cDNAs in Escherichia coli and screened SNAT activity by measuring N‐acetyltryptamine after application with 1 mm tryptamine. GNAT5 was shown to produce high levels of N‐acetyltryptamine in E. coli, suggesting a possible rice SNAT. To confirm SNAT activity, the GNAT5 protein was purified through affinity purification from E. coli culture. The purified recombinant GNAT5 showed high SNAT enzyme activity catalyzing serotonin into N‐acetylserotonin. The values for Km and Vmax were 385 μm and 282 pmol/min/mg protein, respectively. An in vitro enzyme assay of purified SNAT showed N‐acetylserotonin formation to be proportional to enzyme concentration and time, with peak activity at pH 8.8. High substrate concentrations above 1 mm serotonin inhibited SNAT activity. Finally, the mRNA level of SNAT was higher in shoots than in roots, but it was expressed constitutively, unlike N‐acetylserotonin methyltransferase (ASMT), the terminal enzyme in melatonin synthesis. These results suggest that ASMT rather than SNAT is the rate‐limiting enzyme of melatonin biosynthesis in plants.

  DOI：

  10.1111/jpi.12011
• 作为产物：
  描述：

  水 、 褪黑素 生成 2-(5-methoxy-1H-indol-3-yl)ethylazanium 、 乙酸盐
  参考文献：
  名称：

  水稻组蛋白脱乙酰基酶10和拟南芥组蛋白脱乙酰基酶14基因编码N-乙酰5-羟色胺脱乙酰酶，催化N-乙酰5-羟色胺转化为5-羟色胺，这是植物褪黑素生物合成的逆反应。

  摘要：

  在植物中，褪黑激素的产生受到严格的调节，这与其褪色素的前体的产生不同，后者是对衰老和病原体暴露等刺激产生高度诱导作用的。外源性5-羟色胺处理不会在植物中极大地诱导N-乙酰5-羟色胺（NAS）和褪黑激素的产生，这表明从5-羟色胺生物合成褪黑激素的途径中可能存在一个或多个调控基因。在此报告中，我们发现NAS在水稻幼苗中迅速大量转化为5-羟色胺，表明存在N-乙酰5-羟色胺脱乙酰基酶（ASDAC）。为了克隆假定的ASDAC基因，我们筛选了4个被称为组蛋白脱乙酰基酶（HDAC）的基因。）基因，但编码的蛋白质靶向叶绿体或线粒体而不是细胞核。在表达这些基因的4种重组大肠杆菌菌株中，发现一种表达水稻HDAC10基因的大肠杆菌菌株能够响应于NAS处理而产生5-羟色胺。重组纯化的水稻HDAC10（OsHDAC10）蛋白对NAS，N-乙酰酪胺（NAT），N具有ASDAC酶活性-乙酰色胺和褪黑激素，对于NAT具有

  DOI：

  10.1111/jpi.12460

文献信息

• Mechanistic and Structural Analysis of <i>Drosophila melanogaster</i> Arylalkylamine <i>N</i>-Acetyltransferases
  作者：Daniel R. Dempsey、Kristen A. Jeffries、Jason D. Bond、Anne-Marie Carpenter、Santiago Rodriguez-Ospina、Leonid Breydo、K. Kenneth Caswell、David J. Merkler

  DOI：10.1021/bi5006078

  日期：2014.12.16

  Arylalkylamine N-acetyltransferase (AANAT) catalyzes the penultimate step in the biosynthesis of melatonin and other N-acetylarylalkylamides from the corresponding arylalkylamine and acetyl-CoA. The N-acetylation of arylalkylamines is a critical step in Drosophila melanogaster for the inactivation of the bioactive amines and the sclerotization of the cuticle. Two AANAT variants (AANATA and AANATB) have been identified in D. melanogaster, in which AANATA differs from AANATB by the truncation of 35 amino acids from the N-terminus. We have expressed and purified both D. melanogaster AANAT variants (AANATA and AANATB) in Escherichia coli and used the purified enzymes to demonstrate that this N-terminal truncation does not affect the activity of the enzyme. Subsequent characterization of the kinetic and chemical mechanism of AANATA identified an ordered sequential mechanism, with acetyl-CoA binding first, followed by tyramine. We used a combination of pH-activity profiling and site-directed mutagenesis to study prospective residues believed to function in AANATA catalysis. These data led to an assignment of Glu-47 as the general base in catalysis with an apparent pKa of 7.0. Using the data generated for the kinetic mechanism, structure-function relationships, pH-rate profiles, and site-directed mutagenesis, we propose a chemical mechanism for AANATA.
• Cloning and characterization of the serotonin <i>N</i> -acetyltransferase-2 gene (<i>SNAT2</i> ) in rice (<i>Oryza sativa</i> )
  作者：Yeong Byeon、Hyoung Yool Lee、Kyoungwhan Back

  DOI：10.1111/jpi.12339

  日期：2016.9

  AbstractThe penultimate enzyme in melatonin synthesis is serotonin N‐acetyltransferase (SNAT), which exists as a single copy in mammals and plants. Our recent studies of the Arabidopsis snat‐knockout mutant and SNAT RNAi rice (Oryza sativa) plants predicted the presence of at least one other SNAT isogene in plants; that is, the snat‐knockout mutant of Arabidopsis and the SNAT RNAi rice plants still produced melatonin, even in the absence or the suppression of SNAT expression. Here, we report a molecular cloning of an SNAT isogene (OsSNAT2) from rice. The mature amino acid sequences of SNAT proteins indicated that OsSNAT2 and OsSNAT1 proteins had 39% identity values and 60% similarity. The Km and Vmax values of the purified recombinant OsSNAT2 were 371 μm and 4700 pmol/min/mg protein, respectively; the enzyme's optimal activity temperature was 45°C. Confocal microscopy showed that the OsSNAT2 protein was localized to both the cytoplasm and chloroplasts. The in vitro enzyme activity of OsSNAT2 was severely inhibited by melatonin, but the activities of sheep SNAT (OaSNAT) and rice OsSNAT1 proteins were not. The enzyme activity of OsSNAT2 was threefold higher than that of OsSNAT1, but 232‐fold lower than that of OaSNAT. The OsSNAT1 and OsSNAT2 transcripts were similarly suppressed in rice leaves during the melatonin induction after cadmium treatment. Phylogenetic analyses indicated that OsSNAT1 and OsSNAT2 are distantly related, suggesting that they evolved independently from Cyanobacteria prior to the endosymbiosis event.
• Substrate-specific enhancement of the oxidative half-reaction of monoamine oxidase
  作者：Anthony K. Tan、Rona R. Ramsay

  DOI：10.1021/bi00060a003

  日期：1993.3.9

  Monoamine oxidases A and B have identical flavin sites but different, although overlapping, amine substrate specificity. Reoxidation of ternary complexes containing substrate is much faster than of free enzyme, and the enhancement is greater in the A form than the B form. The oxidative half-reaction was studied with a variety of substrates to elucidate the specificity of the effect and to probe the different influences of substrate on the flavin reoxidation in the two forms of the enzyme. The second-order rate constant for the reoxidation was highest with monoamine oxidase A when kynuramine was the ligand (508 x 10(3) M-1 s-1) compared to 4 x 10(3) M-1 s-1 in its absence. MPTP (166 x 10(3) M-1 s-1) also enhanced reoxidation well, but indole substrates stimulated only poorly (e.g., tryptamine, 29 x 10(3) M-1 s-1; serotonin, 50 x 10(3) M-1 s-1). For the A form, the reduction of the flavin was rate-limiting in all cases. For the B form, reoxidation was rate-limiting for beta-phenylethylamine and contributed to the determination of the overall rate with several substrates. The ratio of the enhanced rate of oxidation to the rate of reduction correlated with the redox state of the enzyme in turnover experiments. All the observations are consistent with alternate paths of reoxidation, via either free enzyme or a reduced enzyme-substrate complex. The flux through each path is determined by the relative dissociation constants and rate constants.