Driving enzymatic carboxylation using supercritical CO2

使用超临界 CO2 驱动酶促羧化

• 批准号: 2286841
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2286841
• 关键词: Driving; enzymatic; carboxylation; using; supercritical

While enzymes have evolved to work in aqueous environment, or with biological membranes, industrial applications have often sought to make use of nonaqueous solvents. Recently, the use of supercritical CO2 (scCO2) has been explored by various groups, due the "green" credentials of this solvent. In fact, CO2 is inexpensive, abundant, nontoxic, non-flammable and chemically inert. Furthermore, products are easily recovered upon depressurisation as scCO2 becomes gaseous. Furthermore, unfavourable thermodynamic equilibria in aqueous solvents are suitably altered as in the case of carboxylation by (de)carboxylase enzymes. However, enzyme inactivation can occur, due to pressure, carbamoylation or pH effects. A limited set of examples is available from the literature where natural enzymes are shown to be robust catalysist under scCO2 or CO2/aqueous systems. We wish to explore the suitability of the UbiD family of (de)carboxylases to act as catalysts under such conditions. The mechanism of action of this particular family was discovered in our group, with support from our industrial partner, and the wide spread nature of these enzymes offers a rich biological resource in terms of varied substrate specificity and temperature/pressure/pH stability. In fact, we have shown in preliminary data these enzymes readily act as carboxylases at elevated [CO2]. Hence, we are ideally positioned to explore to what extend UbiD enzymes can catalyse carboxylation in scCO2 or CO2/aqueous systems. We initially will explore the reaction of the thermophylic HmfF enzyme as a model system of biotechnological interest. This enzyme catalyses the carboxylation of furoic acid to furan dicarboxylic acid (FDCA), an alternative green polymer precursor. We now wish to explore the yield and scalability under scCO2 conditions. Furthermore, we plan to explore whether enzyme stability/catalytic properties for scCO2 based catalysis can be improved using (semi)rational mutagenesis. Removal of lysine residues that are subject to carbamoylation will be explored, as well as determining the structural effects of pressure/CO2 on enzyme structure using simulation. The long term goal is to bring these UbiD systems to a sufficient level of productivity to support industrial take up and application.

虽然酶已经发展到在水性环境中或与生物膜一起工作，但工业应用通常寻求利用非水性溶剂。最近，由于超临界CO2（scCO 2）的“绿色”证书，各种小组已经探索了该溶剂的使用。事实上，二氧化碳是廉价的，丰富的，无毒的，不易燃的和化学惰性的。此外，当scCO 2变成气态时，在减压时容易回收产物。此外，在水性溶剂中不利的热力学平衡被适当地改变，如在通过羧化酶（脱羧酶）羧化的情况下。然而，由于压力、氨甲酰化或pH效应，可能发生酶失活。有限的一组实例可从文献中获得，其中天然酶显示出在scCO 2或CO2/水体系下是稳健的催化剂。我们希望探索UbiD家族的（脱）羧酶在这种条件下作为催化剂的适用性。在我们的工业合作伙伴的支持下，我们的团队发现了这个特定家族的作用机制，这些酶的广泛分布性质在不同的底物特异性和温度/压力/pH稳定性方面提供了丰富的生物资源。事实上，我们已经在初步数据中表明，这些酶在[CO2]升高时很容易充当羧化酶。因此，我们处于探索UbiD酶在scCO 2或CO2/水体系中催化羧化的理想位置。我们最初将探索嗜热HmfF酶的反应作为生物技术兴趣的模型系统。这种酶催化糠酸羧化为呋喃二羧酸（FDCA），一种替代的绿色聚合物前体。我们现在希望探索scCO 2条件下的产量和可扩展性。此外，我们计划探索是否可以使用（半）理性诱变来改善基于scCO 2的催化的酶稳定性/催化性质。将探讨去除赖氨酸残基的氨甲酰化，以及确定压力/CO2对酶结构的结构影响，使用模拟。长期目标是使这些UbiD系统达到足够的生产力水平，以支持工业应用。