Investigating multi-functional cytochromes P450 from gibberellin phytohormone biosynthesis

通过这一奖项，美国国家科学基金会化学部的生命过程化学计划资助爱荷华州立大学的鲁本·彼得斯博士研究某些酶如何催化天然产品的生产。这些天然产品具有多种工业用途，包括用作香料和香料。在这些化合物的生产中，酶起着关键作用，通常只需插入一个氧原子，但现在已知能够进行更复杂的化学转化。在导致一种重要的植物激素产生的生物合成途径中，已经确定了几种这样的多功能酶，这些酶将在本项目中进行详细的研究。研究人员正在阐明这些酶是如何完成化学反应的。该项目具有明显的生物技术相关性，因为目标酶之一已经引起了人们对生产天然甜味剂的兴趣。此外，参与这项工作的研究生和本科生正在获得与工业相关的酶的尖端研究方面的专业知识。最后，高中科学教师的加入将这一项目的范围扩大到了K-12社区。本项目研究细胞色素P450(Cyps)，这是一种血红素硫代单加氧酶，通常催化羟化，但能够进行更复杂的反应。这可以从赤霉素(GA)的生物合成中看出，赤霉素是一种植物激素，它对植物-微生物相互作用的影响导致了植物相关微生物(包括细菌)中GA生物合成的独立进化，最近从细菌中发现了相关的多功能环氧合酶。这些可溶酶可以修改，以进行更详细的研究。通过这些研究，阐明了细菌GA生物合成多功能细胞色素P的反应机理和酶的结构-功能关系，进一步了解了如何改变基本细胞色素P的催化循环以完成更复杂/不寻常的反应，这是当前酶学/生物无机化学中的突出问题之一，具有明显的生物技术意义。

With this award, the Chemistry of Life Processes Program in the Chemistry Division of NSF is funding Dr. Reuben Peters from Iowa State University for studies into how certain enzymes catalyze the production of natural products. These natural products have a variety of industrial uses, including as flavors and fragrances. Key roles in the production of these compounds are played by enzymes which typically simply insert an atom of oxygen, but are now known to be capable of much more complex chemical transformations. Several such multi-functional enzymes have been identified in the biosynthetic pathway leading to production of an important plant hormone and these will be studied in detail in this project. The researchers are elucidating how these enzymes accomplish their chemical reactions. The project has clear biotechnological relevance, as one of the enzymes targeted has already drawn interest for use in the production of natural sweeteners. Additionally the graduate and undergraduate students participating in this work are gaining expertise in cutting-edge studies of enzymes with industrial relevance. Finally the inclusion of high-school science teachers extends the reach of this project to the K-12 community. This project investigates cytochromes P450 (CYPs), which are heme-thiolate mono-oxygenases that generally catalyze hydroxylation, but are capable of much more complex reactions. This can be seen in biosynthesis of gibberellin (GA), a phytohormone whose effect on plant-microbe interactions has led to the independent evolution of GA biosynthesis in plant-associated microbes, including bacteria, from which the relevant multi-functional CYPs have been recently identified. These soluble enzymes are amendable to more detailed investigations. Through these studies, the reaction mechanisms and enzymatic structure-function relationships of the multi-functional CYPs from bacterial GA biosynthesis are being elucidated, furthering understanding of how the basic CYP catalytic cycle is modified to accomplish more complex/unusual reactions, which is currently one of the outstanding questions in enzymology/bioinorganic chemistry, with clear biotechnological implications.