双重乳标记的帕丘利酒精来自单一标记的[2-(2) H(1)]法纳西二酸盐的循环,由重组帕丘洛尔合成酶催化
Juan A Faraldos1, Shuiqin Wu, Joe Chappell
1Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|February 13, 2010
概括
这项研究揭示了如何使用带标记的法二酸盐 (farnesyl diphosphate) 制造帕丘醇合成酶 (PTS). 这项研究澄清了酶的机制,确定了1,3-化物转移和一种新的中间体.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 有机化学 有机化学
背景情况:
- 帕丘醇合成酶 (PTS) 是聚烯生物合成中的一个关键酶.
- 了解PTS的催化机制对于阐明四烯形成途径至关重要.
研究的目的:
- 用同位素标记的基质研究帕丘醇合成酶 (PTS) 的反应机制.
- 识别中间体并描述PTS催化反应的立体化学.
主要方法:
- 在同位素纯 [2-(2) H(1) ](E,E) -法内西二酸盐与重组PTS的化.
- 广泛的核磁共振 (NMR) 分析 (1H,13C,2H NMR,HMQC,同源合).
- 低分辨率的快速电离质谱 (FIMS) 和同位素比计算.
主要成果:
- 一种混合的单化 ([5-(2) H(1) ]-patchoulol) 和脱化 ([5,12-(2) H(2) ]-patchoulol) 的 patchoulols 在 2:1 的比率被制造出来.
- 在C5 (100%) 和C12 (30-35%) 证实了标签,表明1,3-化物转移机制.
- 碳化合物副产品 (β-patchoulene,alpha-guaiene) 显示出乳耗尽,识别了标签在patchoulol-d中的来源.
结论:
- 结果证实了1,3-化物转移机制在patchoulol生物合成中,排除了其他途径.
- 一种新型的外循环中间体,[7,10:1,5]patchoul-4(12)-ene,被提议解释脱化patchoul.ol的形成.
- 对PTS活性部位的结构洞察力表明,氨酸410在促进氨酸转移方面发挥了作用.
相关概念视频
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
Preparation of Diols and Pinacol Rearrangement
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.
Long-patch Base Excision Repair
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:


