Biochemical, genetics and molecular biology of the bacterial biphenyl catabolic pathway enzymes

细菌联苯分解代谢途径酶的生化、遗传学和分子生物学

• 批准号: 39579-2007
• 负责人: Sylvestre, Michel
• 金额: $ 3.28万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=390311
• 关键词: Biochemical; genetics; molecular; biology; bacterial

Chirality is a key factor in the efficacy of many drugs and agrochemicals. In addition, complex compounds such as hydroxylated heterocyclic aromatics and flavonoids are regarded as very promising for the prevention and treatment of cancers and cardio-vascular diseases. Plants are currently the major source for these chemicals, but the synthesis of novel derivatives exhibiting improved biological properties is often difficult or impractical. Furthermore, in the context of the green chemistry concept, new more selective and more environmentally friendly approaches to manufacture these biologically specific fine chemicals will be required. This includes the use of biocatalysts to catalyze stereospecific reactions. In the present proposal we will focus on the biochemical properties of the biphenyl dioxygenase (BPDO), which catalyses the stereospecific dioxygenation of biphenyl to generate a cis-dihydrodiol metabolite. The substrates for BPDOs include many benzene or diphenyl skeletons, whose hydrogens are substituted with either methyl, ethyl, vinyl, carboxyl, halogenated or nitro groups. It can also oxygenate to cis-diol bicyclic- or tricyclic-fused heterocyclic aromatics such as quinoline, dibenzofuran and phenanthridine. Understanding how the BPDO catalytic pocket interacts with the substrate (and substrate analogs) to bind them and orient them into the catalytic pocket and understanding the mechanisms by which the enzyme can evolve to enhance its specificity toward new substrate analogs will help design novel biocatalysts useful in biotechnological processes for the destruction of persistent pollutants or biocatalytic processes for green production of chemicals. The objectives of this proposal are to pursue with some of the basic investigations: A- regarding the biochemistry of the BPDO to get a better insight about the mechanism of catalytic activity and B- regarding the dynamics of BPDO evolution, answering specific questions about the protein domains and amino acid residues representing the major determinants of substrate specificity, regiospecificity and stereospecificity and how they interact with the substrate.

手性是许多药物和农业化学物质功效的关键因素。此外，对于预防和治疗癌症和心脏血管疾病的预防和治疗，诸如羟基化杂环芳香族和类黄酮等复杂化合物被认为非常有前途。目前，植物是这些化学物质的主要来源，但是表现出改善生物学特性的新型衍生物的合成通常很困难或不切实际。此外，在绿色化学概念的背景下，将需要更具选择性和更环保的方法来制造这些生物学特定的精细化学物质。这包括使用生物催化剂来催化立体反应。在本建议中，我们将重点关注双苯基二氧酶（BPDO）的生化特性，该酶（BPDO）催化了双苯基的立体杂种二氧化量，从而产生了CIS-二氢二醇代谢物。 BPDOS的底物包括许多苯或二苯基骨骼，其氢被用甲基，乙基，乙烯基，羧基，卤代或硝基化组取代。它还可以对顺式二醇或三环融合的杂环芳香剂（例如喹啉，二苯并五呋喃和苯噻烷氨酸）充氧。了解BPDO催化口袋如何与底物（和底物类似物）相互作用，以将它们结合并将其定向到催化口袋中，并了解该酶可以发展为增强其针对新底物类似物的特异性的机制，这些机制可帮助设计在生物技术生产过程中有用的生物剂量的生物效应，使其对生物技术的生产效果进行持久构成或持久性化学效应，或者是持久化化学物质构成的。该提案的目标是进行一些基本研究：a-关于BPDO的生物化学，以更好地了解催化活性的机制和关于BPDO进化的动态的机制，回答有关蛋白质领域和氨基酸的具体问题，这些问题与代表基本范围的主要确定性相互作用和定型性，定型性，定型性和定型性。