Identification of the Dinuclear Metallo-Cofactor and Elucidation of the Reaction Mechanism of the Aldehyde Decarbonylase from the Alkane-producing Cyanobacterium Nostoc Punctiforme

分子生物科学计划的这一奖项支持宾夕法尼亚州立大学从产烷烃的蓝藻发菜(NP)中研究乙醛脱羧酶(AD)的工作。NP-AD催化的反应是蓝藻生物合成烷烃的两个反应中的第二个。因此，该项目支持的研究旨在阐明蓝藻产生烷烃的关键步骤的详细化学步骤。由于蓝藻具有环境多样性、生长迅速、基因可变以及(最重要的)光合作用，它们正被积极用作开发可再生能源的载体。这些研究包括鉴定NP AD活性所需的双核金属辅酶因子，并结合生化和生物物理方法确定NP AD的反应机理。脂肪酸的利用表明，可溶性NP AD设计了一种新的策略来获得这种水不溶底物。还将评估NP AD获得底物的机制，以区分通道机制和膜靶向。该项目使用一套通用的实验策略来评估烷烃的生物合成。这些拟议的研究结果将为酶金属中心的新的化学性质提供有价值的信息。这项工作的更广泛影响是双重的。首先，生物化学和无机化学交界处的研究领域是非常跨学科的，为学生和博士后学者提供了各种方法的培训。宾夕法尼亚州立大学和其他机构的生物无机化学家将为大约80名学生和博士后学者举办讲习班，作为这一研究领域使用的许多方法的独特培训机会。其次，这项研究与可再生能源的发展相关，因为利用蓝藻生产烷烃是一种很有前途的生物燃料生产策略。这一过程特别环保，因为该过程是(I)碳中性(烷烃产品中的所有碳都来自蓝藻固定的二氧化碳)和(Ii)由太阳能驱动(由于蓝藻的光合作用性质)。该项目将有助于合理设计用于提高生物燃料生产的基因工程蓝藻。

This award in the molecular biosciences program supports work at the Pennsylvania State University to study the enzyme aldehyde decarbonylase (AD) from the alkane-producing cyanobacterium Nostoc punctiforme (Np). The reaction catalyzed by Np AD is the second of the two reactions in the biosynthesis of alkanes by cyanobacteria. Thus, research supported by this project aims at elucidating the detailed chemical steps of the key alkane-producing step in cyanobacteria. Because cyanobacteria are environmentally versatile, rapidly growing, genetically alterable, and (most importantly) photosynthetic, they are being actively pursued as a vehicle for development of renewable energy. These studies include the identification of the dinuclear metallocofactor required for activity of Np AD and determination of the reaction mechanism of Np AD by a combination of biochemical and biophysical approaches. The utilization of fatty acids suggests that the soluble Np AD has devised a novel strategy to obtain this water insoluble substrate. The mechanism of substrate acquisition by Np AD will also be evaluated to differentiate between a channeling mechanism and membrane targeting. This project uses a versatile set of experimental strategies to evaluate the biosynthesis of alkanes. The results from these proposed studies will provide valuable information on new chemical properties of an enzyme metal center. The broader impacts of this work are two-fold. First, the research area at the interface of biological and inorganic chemistry is very interdisciplinary and offers students and postdoctoral scholars to be trained in a wide variety of methods. A workshop will be offered by bioinorganic chemists from Penn State and other institutions to approximately 80 students and postdoctoral scholars as a unique training opportunity in many of the methods used in this research field. Second, the research is relevant for the development of renewable energy, because the use of cyanobacteria for alkane production is a promising strategy for biofuel production. This process is particularly environmentally friendly, because the process is (i) carbon neutral (all carbon found in the alkane product derives from carbon dioxide fixed by the cyanobacteria) and (ii) driven by solar energy (due to the photosynthetic nature of cyanobacteria). This project will aid in the rational design of genetically engineered cyanobacteria for enhanced biofuel production.