2,3-二甲基-5-[(2E,6E,10E,14E,18E,22E,26E,30E)-3,7,11,15,19,23,27,31,35-九甲基三十六碳-2,6,10,14,18,22,26,30,34-壬烯基]苯-1,4-二醇 | 3819-09-8

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 异戊烯醇脂质
• 中文名称: 2,3-二甲基-5-[(2E,6E,10E,14E,18E,22E,26E,30E)-3,7,11,15,19,23,27,31,35-九甲基三十六碳-2,6,10,14,18,22,26,30,34-壬烯基]苯-1,4-二醇
• 英文名称: Plastoquinol-9
• 英文别名: 2,3-dimethyl-5-[(2E,6E,10E,14E,18E,22E,26E,30E)-3,7,11,15,19,23,27,31,35-nonamethylhexatriaconta-2,6,10,14,18,22,26,30,34-nonaenyl]benzene-1,4-diol
• CAS: 3819-09-8
• 化学式: C₅₃H₈₂O₂
• 分子量: 751.2
• InChiKey: IJBLJLREWPLEPB-IQSNHBBHSA-N

物化性质

• 沸点：
  797.0±48.0 °C(Predicted)
• 密度：
  0.936±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  18.1
• 重原子数：
  55
• 可旋转键数：
  26
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.55
• 拓扑面积：
  40.5
• 氢给体数：
  2
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  7,7',8,8',11,11',12,12'-八氢-psi,psi-胡罗卜素 、 质体醌 生成 9,15,9'-Tri-cis-zeta-carotene 、 2,3-二甲基-5-[(2E,6E,10E,14E,18E,22E,26E,30E)-3,7,11,15,19,23,27,31,35-九甲基三十六碳-2,6,10,14,18,22,26,30,34-壬烯基]苯-1,4-二醇
  参考文献：
  名称：

  ?-Carotene cis isomers as products and substrates in the plant poly-cis carotenoid biosynthetic pathway to lycopene

  摘要：

  The plant carotenoid biosynthetic pathway to cyclic carotenes proceeds via carotene precursors in cis configuration. Involvement of individual isomers was elucidated by genetic complementation of desaturations and in vitro reactions of the corresponding enzyme. Determination of substrate and product specificity of phytoene and zeta-carotene desaturase revealed that 15-cis-phytoene is converted to 9,15,9'-tricis-zeta-carotene with 15,9'-dicis-phytofluene as intermediate by the first desaturase. Prior to a subsequent conversion by zeta-carotene desaturase, the 15-cis double bond of 9,15,9'-tricis-zeta-carotene has to be ( photo) isomerized to all-trans. Then, the resulting 9,9'-dicis-zeta-carotene is utilized by zeta-carotene desaturase via 7,9,9'-tricis-neurosporene to 7,9,7', 9'-tetracislycopene. Other zeta-carotene isomers that are assumed to be spontaneous isomerization products were not converted, except for the asymmetric 9-cis-zeta-carotene. This isomer is desaturated only to 7,9-dicis-neurosporene resembling a dead-end of the pathway. Prolycopene, the product of the desaturation reactions, is finally isomerized by a specific isomerase to all-trans-lycopene, which is a prerequisite for cyclization to beta-carotene. The 5-cis-lycopene and the 9-cis-and 13-cis-beta-carotene isomers detected in leaves are thought to originate independently from cis precursors by non-enzymatic isomerization of their all-trans forms.

  DOI：

  10.1007/s00425-004-1395-2

文献信息

• Cyanobacterial photosystem II at 2.9-Å resolution and the role of quinones, lipids, channels and chloride
  作者：Albert Guskov、Jan Kern、Azat Gabdulkhakov、Matthias Broser、Athina Zouni、Wolfram Saenger

  DOI：10.1038/nsmb.1559

  日期：2009.3

  20 protein subunits and complete modeling of all 35 chlorophyll a molecules and 12 carotenoid molecules, 25 integral lipids and 1 chloride ion per monomer. The presence of a third plastoquinone Q(C) and a second plastoquinone-transfer channel, which were not observed before, suggests mechanisms for plastoquinol-plastoquinone exchange, and we calculated other possible water or dioxygen and proton channels

  光系统 II (PSII) 是位于光合类囊体膜中的大型同源二聚体蛋白质辅因子复合物，充当光驱动水：质体醌氧化还原酶。来自Thermosynechococcus elongatus 的PSII 的晶体结构在2.9-A 分辨率下允许明确分配所有20 个蛋白质亚基并完整建模所有35 个叶绿素a 分子和12 个类胡萝卜素分子、25 个整体脂质和每个单体1 个氯离子。之前未观察到的第三个质体醌 Q(C) 和第二个质体醌转移通道的存在表明了质体醌-质体醌交换的机制，我们计算了其他可能的水或双氧和质子通道。从氙衍生物获得的假定氧位置表明脂质在氧扩散到 PSII 细胞质侧中的作用。
• The role of plastoquinone and β-carotene in the primary reaction of plant Photosystem II
  作者：David B. Knaff、Richard Malkin、J. Clark Myron、Marshall Stoller

  DOI：10.1016/0005-2728(77)90041-x

  日期：1977.3

  the primary reaction of Photosystem II, as evidenced by restoration of low-temperature photooxidation of P-680, could be obtained by the addition of plastoquinone A but not by the addition of beta-carotene. The addition of beta-carotene plus plastoquinone A restored the C-550 absorbance change. These results indicate that plastoquinone functions as the primary electron acceptor of Photosystem II and

  用0.2％的甲醇在己烷中的溶液萃取Triton Photosystem II叶绿体片段3小时，可去除原始制剂中90％至95％的质体醌。单次激光闪光后，提取的碎片（叶绿素：质体醌比例为900：1）在15 K下未显示P-680光氧化。提取的碎片在77 K时也没有显示出光诱导的C-550吸光度变化。通过添加质体醌A，可以恢复P-680的低温光氧化，从而可以重建Photosystem II的一级反应。但不能通过添加β-胡萝卜素来实现。添加β-胡萝卜素和质体醌A可以恢复C-550的吸光度变化。
• Highly Divergent Methyltransferases Catalyze a Conserved Reaction in Tocopherol and Plastoquinone Synthesis in Cyanobacteria and Photosynthetic Eukaryotes
  作者：Z. Cheng

  DOI：10.1105/tpc.013656

  日期：2003.10.1

  Tocopherols are lipid-soluble compounds synthesized only by photosynthetic eukaryotes and oxygenic cyanobacteria. The pathway and enzymes for tocopherol synthesis are homologous in cyanobacteria and plants except for 2-methyl-6-phytyl-1,4-benzoquinone/2-methyl-6-solanyl-1,4-benzoquinone methyltransferase (MPBQ/MSBQ MT), which catalyzes a key methylation step in both tocopherol and plastoquinone (PQ) synthesis. Using a combined genomic, genetic, and biochemical approach, we isolated and characterized the VTE3 (vitamin E defective) locus, which encodes MPBQ/MSBQ MT in Arabidopsis. The phenotypes of vte3 mutants are consistent with the disruption of MPBQ/MSBQ MT activity to varying extents. The ethyl methanesulfonate–derived vte3-1 allele alters tocopherol composition but has little impact on PQ levels, whereas the null vte3-2 allele is deficient in PQ and α- and γ-tocopherols. In vitro enzyme assays confirmed that VTE3 is the plant functional equivalent of the previously characterized MPBQ/MSBQ MT (Sll0418) from Synechocystis sp PCC6803, although the two proteins are highly divergent in primary sequence. Sll0418 orthologs are present in all fully sequenced cyanobacterial genomes, Chlamydomonas reinhardtii, and the diatom Thalassiosira pseudonana but absent from vascular and nonvascular plant databases. VTE3 orthologs are present in all vascular and nonvascular plant databases and in C. reinhardtii but absent from cyanobacterial genomes. Intriguingly, the only prokaryotic genomes that contain VTE3-like sequences are those of two species of archea, suggesting that, in contrast to all other enzymes of the plant tocopherol pathway, the evolutionary origin of VTE3 may have been archeal rather than cyanobacterial. In vivo analyses of vte3 mutants and the corresponding homozygous Synechocystis sp PCC6803 sll0418::aphII mutant revealed important differences in enzyme redundancy, the regulation of tocopherol synthesis, and the integration of tocopherol and PQ biosynthesis in cyanobacteria and plants.

  chocystis PCC6800的基因组分析表明，VTE3编码的MPBQ/MSBQ MT在拟南芥中具有多种功能。vte3突变体的表型与MPBQ/MSBQ MT活性在不同程度上的破坏相一致。甲基磺酸乙酯衍生的vte3-1等位基因改变了生育酚的组成，但对PQ水平的影响不大，而无效的vte3-2等位基因缺乏PQ和α-生育酚和γ-生育酚。体外酶分析证实，VTE3是植物功能等同于先前从Synechocystis sp PCC6803中鉴定的MPBQ/MSBQ MT（Sll0418），尽管这两种蛋白质在主要序列上差异很大。Sll0418同源物存在于所有完全测序的蓝藻基因组、Chlamydomonas reinhardtii和硅藻Thalassiosira pseudonana中，但不存在于维管植物和非维管植物数据库中。VTE3同源物存在于所有维管植物和非维管植物数据库以及C. reinhardtii中，但不存在于蓝藻基因组中。有趣的是，唯一含有VTE3样序列的原核生物基因组是两种古细菌的基因组，这表明与植物生育酚途径的所有其他酶相反，VTE3的进化起源可能是古细菌而不是蓝藻
• The role of 2-methyl-6-phytylbenzoquinone methyltransferase in determining tocopherol composition in <i>Synechocystis</i> sp. PCC6803
  作者：David K. Shintani、Zigang Cheng、Dean DellaPenna

  DOI：10.1016/s0014-5793(01)03223-9

  日期：2002.1.30

  A putative 2‐methyl‐6‐phytylbenzoquinone (MPBQ) methyltransferase gene, SLL0418, was identified from the Synechocystis PCC6803 genome based on its homology to previously characterized γ‐tocopherol methyltransferases. Genetic and biochemical evidence confirmed open reading frame (ORF) SLL0418 encodes a MPBQ methyltransferase. An SLL0418 partial knockout mutant accumulated β‐tocopherol with no effect in the overall tocopherol content of the cell. In vitro assays of the SLL0418 gene expressed in Escherichia coli showed the enzyme efficiently catalyzes methylation of ring carbon 3 of MPBQ. In addition, the enzyme also catalyzes the methylation of ring carbon 3 of 2‐methyl‐6‐solanylbenzoquinol in the terminal step of plastoquinone biosynthesis.