Mechanism of fungal polysaccharide monooxygenases

真菌多糖单加氧酶的机制

• 批准号: 1565770
• 负责人: Michael Marletta
• 金额: $ 50万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1565770&HistoricalAwards=false
• 关键词: Mechanism; fungal; polysaccharide; monooxygenases

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Michael Marletta from The Scripps Research Institute to investigate the recently discovered polysaccharide monooxygenases (PMOs), enzymes that catalyze the degradation of cellulose. Cellulose is the major constituent of biomass in nature. Despite years of study, the efficient and economical degradation of cellulose remains a limiting factor in the industrial production of biofuels from cellulose. PMOs could help to overcome the prohibitive costs associated with cellulose degradation. PMOs use a copper active site to oxidize specific positions on cellulose. This project will investigate the chemistry by which these enzymes break the cellulose backbone and the determinants of regioselective (i.e. specific site) oxidation. The research contributes to the current quest for green and sustainable energy, creates opportunities for the education of future scientists capable of work in the field of bioenergy, and raises the awareness of college and high school students of STEM careers. The objective of this project is to gain insight into the mechanism by which the newly discovered oxygen- and copper-dependent fungal PMOs catalyze the regioselective hydroxylation and oxidation of glycosidic bonds of crystalline cellulose. The research will focus on the direct identification and characterization of the copper-based species in the catalytic cycle. The kinetics of interconversion of these species, the electron transfer during catalysis, the role of the conserved active site hydrogen bonding network, and the factors governing the regioselectivity of the reactions catalyzed by PMO will be studied using site directed mutagenesis, rapid kinetic techniques, spectroscopic methods and biochemical assays. The proposed studies will contribute fundamental knowledge to the metal-catalyzed oxygen activation chemistry and to the development of alternative fuels.

通过这个奖项，化学部门的生命过程化学项目资助了斯克里普斯研究所的Michael Marletta博士，以研究最近发现的多糖单加氧酶（PMOs），这种酶催化纤维素的降解。纤维素是自然界生物质的主要成分。尽管经过多年的研究，纤维素的高效和经济降解仍然是纤维素生物燃料工业生产的限制因素。PMOs可以帮助克服与纤维素降解相关的过高成本。PMOs使用铜活性位点氧化纤维素上的特定位置。该项目将研究这些酶破坏纤维素骨架的化学作用以及区域选择性（即特定位点）氧化的决定因素。这项研究有助于当前对绿色和可持续能源的追求，为能够在生物能源领域工作的未来科学家的教育创造机会，并提高大学和高中生对STEM职业的认识。该项目的目的是深入了解新发现的依赖氧和铜的真菌PMOs催化结晶纤维素糖苷键的区域选择性羟基化和氧化的机制。研究将集中在催化循环中铜基物质的直接识别和表征。这些物种的相互转化动力学，催化过程中的电子转移，保守活性位点氢键网络的作用，以及控制PMO催化反应区域选择性的因素将通过位点定向诱变，快速动力学技术，光谱方法和生化分析进行研究。所提出的研究将为金属催化氧活化化学和替代燃料的开发提供基础知识。