Fluorovinyl thioethers as stereoelectronic mimetics of acyl co-enzyme-A enol/ates

氟乙烯基硫醚作为酰基辅酶 A 烯醇/酯的立体电子模拟物

• 批准号: EP/N03001X/1
• 负责人: David O'Hagan
• 金额: $ 51.08万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN03001X%2F1
• 关键词: Fluorovinyl; thioethers; stereoelectronic; mimetics; acyl

Enzymes are biological catalysts that carry out the reactions of metabolism. They are found in all living forms such as higher mammals, plants and bacteria. If an enzyme reaction in a plant or a bacterium can be selectively inhibited, then there are prospects of developing agrochemical agents such as herbicides if we can inhibit plant enzymes, or antibiotics if we inhibit bacterial enzymes.Enzyme inhibition is an established strategy in agrochemicals and pharmaceuticals research.One way of designing enzyme inhibitors is to mimic, at the molecular level, an unstable intermediate in the chemical process, because the enzyme is good at binding to unstable intermediates, and processing them efficiently. That is how they carry out their catalysis. The ingenuity for the researcher comes in trying to design a suitable stable mimic of an unstable intermediate. This is a challenge, but if it can be achieved, then a strategy for enzyme inhibition opens up.This proposal aims to mimic enol or/and enolate intermediates, that are thought to be transient on the surface of enzymes, when they are carrying out their catralytic function. An enolate has an oxygen atom attached to a double bond. This is very unstable as it can rearrange to a more stable carbonyl form. The enolate however is stabilised by interactions with the enzyme surface, as a means of its proper functioning.In this proposal, the oxygen attached to the enolate double bond will be replaced by a fluorine. This is a vinylfluoride. This is stable, and we have shown by computer modelling that it has approximately the same electronic profile as an enolate. This is a new idea, and the proposal will aim to explore this at the enzyme level.Two of the three enzymes selected are important to the agrochemical industry, enzymes that have been the focus of inhibition to prepare herbicides. Thes enzymes are acetyl CoA carboxylase (ACC), trans enoyl Co-A-reductase. The enzymes utilise co-enzyme-A esters. Co-enzyme-A is a relatively complex biomolecule, and it challenging to prepare derivatives of it in the way that is envisaged. However in preliminary work we have developed a chemical method to prepare the required fluorovinyl thioether, and a biochemical (enzyme) method to eleborate the synthesised motif into a fully formed co-enzyme-A derivative. The excitement now is to prepare full co-enzyme-A derivatives of the fluorovinyl thioether motif, and assess their ability to bind to and also inhibit appropriate enzymes.One aspect of the proposal is to assess how important the fluorine atom is in mimicking the oxygen atom. Therefore analogues will be prepared with fluorine, and then without fluorine, replacing it for a hydrogen. The working hypothesis anticipates that there will be a significant fluorine effect. There are several methods for assessing if the co-enzyme-A derivatives will bind to the enzymes, and also for assessing their relative affinities. This involves enzymes assays, and assessing if the motif is a good inhibitor (strong binder). This can also be assessed by calorimetry (ITC), where good binding leads to an exotherm, and heat is evolved. The lab has good instrumentation for detailed enzyme assay and calorimetry analysis.We also plan to co-crystallise our elaborate co-enzyme-A derivatives with the enzymes. These are mimetics of reactive intermediates (enolates) and they should bind tightly to the enzyme surface. X-ray analysis will enable us to look very closley as to how this mimetic binds into the enzyme pocket.At the end of the programme we will be able demonstrate how to introduce and manipulate this new fluorine containing motif, and its potential in enzyme inhibition. The focus here is orientated towards agrochemicals reserach, however the principles that emerge will be equally applicable to pharmaceuticals research, and rational approachedsto enzyme inhibition more generally.

酶是进行新陈代谢反应的生物催化剂。它们存在于所有生物形式中，如高等哺乳动物，植物和细菌。如果植物或细菌中的酶反应可以被选择性抑制，那么就有希望开发农用化学品，例如除草剂（如果我们可以抑制植物酶）或抗生素（如果我们抑制细菌酶）。酶抑制是农用化学品和药物研究中的既定策略。设计酶抑制剂的一种方法是在分子水平上模拟化学过程中不稳定的中间体，因为这种酶善于与不稳定的中间体结合，并有效地处理它们。这就是它们如何进行催化作用的。研究人员的聪明才智在于试图设计一种合适的稳定模拟物来模拟一种不稳定的中间体。这是一个挑战，但如果它可以实现，那么酶抑制的策略打开了。这个建议的目的是模拟烯醇或/和烯醇化中间体，这被认为是短暂的酶的表面上，当他们进行他们的催化功能。烯醇化物有一个氧原子连接在双键上。这是非常不稳定的，因为它可以重新排列成更稳定的羰基形式。然而，烯醇化物通过与酶表面的相互作用而稳定，作为其正常功能的一种手段。在这个提议中，连接在烯醇化物双键上的氧将被氟取代。这是氟乙烯这是稳定的，我们已经通过计算机建模表明，它具有与烯醇化物大致相同的电子分布。这是一个新的想法，该提案将致力于在酶水平上探索这一点。所选的三种酶中有两种对农业化学工业很重要，这些酶一直是制备除草剂的抑制剂的焦点。这些酶是乙酰辅酶A羧化酶（ACC）、反式烯酰辅酶A还原酶。酶利用辅酶A酯。辅酶A是一种相对复杂的生物分子，以设想的方式制备其衍生物具有挑战性。然而，在初步工作中，我们已经开发了一种化学方法来制备所需的氟乙烯基硫醚，以及一种生物化学（酶）方法来将合成的基序eleborate成完全形成的辅酶A衍生物。现在令人兴奋的是制备完全的氟乙烯基硫醚基序的辅酶A衍生物，并评估它们结合并抑制适当酶的能力。该提案的一个方面是评估氟原子在模拟氧原子中的重要性。因此，类似物将用氟制备，然后不含氟，用氢取代它。工作假设预计将有一个显着的氟效应。有几种方法用于评估辅酶A衍生物是否与酶结合，以及评估它们的相对亲和力。这涉及酶测定，并评估基序是否是良好的抑制剂（强结合剂）。这也可以通过量热法（ITC）进行评估，其中良好的结合导致热释放。实验室有良好的仪器进行详细的酶分析和量热分析。我们还计划将我们精心制作的辅酶A衍生物与酶共结晶。这些是活性中间体（烯醇化物）的模拟物，它们应该与酶表面紧密结合。X射线分析将使我们能够非常仔细地观察这种模拟物如何结合到酶口袋中。在节目的最后，我们将能够展示如何引入和操纵这种新的含氟基序，以及它在酶抑制方面的潜力。这里的重点是面向农用化学品的研究，但出现的原则将同样适用于药物的研究，和合理的方法酶抑制剂更普遍。