Collaborative Research: Bacterial manganese(IV) oxide biomineralization: Mechanism of Mn(II,III) oxidation by the multicopper oxidase complex

合作研究：细菌氧化锰（IV）生物矿化：多铜氧化酶复合物氧化锰（II，III）的机制

• 批准号: 1410688
• 负责人: Bradley Tebo
• 金额: $ 40.08万
• 依托单位: Oregon Health & Science University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410688&HistoricalAwards=false
• 关键词: Collaborative; Research; Bacterial; manganese; IV

With this award, the Chemistry of Life Processes Program is funding Dr. Bradley Tebo of Oregon Health and Science University and Dr. Thomas Spiro of the University of Washington for a collaborative research investigation of how manganese is oxidized in living systems. The substances formed in this oxidation are various forms of manganese oxide. These minerals are some of the strongest oxidants found in the environment and play important roles in both a biological and a geological sense. They are often called "scavengers of the sea" because of their great ability to absorb toxic substances. The chemical details of the biological oxidation of manganese ions and formation of manganese oxides by enzymes are not yet elucidated. The research of Dr. Tebo and Dr. Spiro examines the role of a specific enzyme, multicopper manganese oxidase, or MCO, that is derived from a bacterium that lives in the ocean. In previous research, the investigators were able to isolate the enzyme and, in the process, found that additional proteins seem necessary for the manganese oxidation. The current research addresses the nature of these newly discovered "helper" proteins and the chemistry catalyzed by MCO and the helper proteins; the results can be used to shed light on how the bacterium converts manganese in seawater to how the mineral exerts its important role in detoxifying seawater. The work impacts our understanding of several areas of science including oceanography, geology, biology and biochemistry. Another broad impact is through the inclusion of students at all educational levels, including high school, in the research. The investigators disseminate insights obtained from research to the general public through a science-in-art project.A collaborative approach involving the two groups from different universities is being used to study the mechanism of bacterial manganese Mn(II) oxidation and manganese oxide production by the multicopper Mn oxidase (MCO) from Bacillus sp. PL-12. The formation of manganese oxide by bacterial oxidation of dissolved Mn(II) is important in aquatic and soil environments and is a key pathway in the global Mn cycle, which supports life through the Mn catalytic centers of many enzymes. This process has received increased technological interest because it leads to highly-reactive, nanoparticulate minerals, which can break down organic molecules and adsorb other metal ions, thereby controlling the distribution and bioavailability of many toxic and essential elements. An interdisciplinary effort using tools from chemistry, biochemistry and biophysics is being used to elucidate the mechanism of manganese oxidation by MCO. The biochemical mechanism by which this oxidation, as well as MnO2 mineralization, occurs is poorly understood. Multicopper oxidase enzymes have been implicated as catalysts for the Mn(II) oxidation in many model systems for Mn(II)-oxidizing bacteria, including the recently purified Mn oxidase complex from Bacillus sp. PL-12. In this project, the structure and mechanism by which the Mn oxidase complex from Bacillus sp. carries out two sequential one-electron oxidation steps and mineralizes Mn is being elucidated. The specific objectives of the research are: 1) to characterize the copper centers of the Mn oxidase complex; 2) to determine the course of Mn oxidation and oxygen entry; 3) to characterize polynuclear intermediates formed on the pathway to MnO2; 4) to describe the role of ancillary proteins required for the expression of the active complex; and 5) to elucidate the structure of the enzyme complex and emerging oxides. X-ray crystallography and spectroscopic methods are being used in conjunction with basic biochemistry techniques to achieve these objectives.

通过该奖项，《生命过程》计划的化学计划正在为俄勒冈州健康与科学大学的Bradley Tebo博士以及华盛顿大学的Thomas Spiro博士提供合作研究调查，以研究如何在生命系统中氧化。在这种氧化中形成的物质是各种形式的氧化锰。这些矿物质是在环境中发现的一些最强的氧化剂，并且在生物学和地质意义上都起着重要作用。它们通常被称为“海洋清道夫”，因为它们具有吸收有毒物质的强大能力。尚未阐明锰离子生物氧化的化学细节以及酶形成锰氧化物的化学细节尚未阐明。 Tebo博士和Spiro博士的研究研究了特定酶，多型锰氧化酶或MCO的作用，该酶是源自居住在海洋中的细菌。在先前的研究中，研究人员能够隔离酶，在此过程中，发现其他蛋白质似乎是锰氧化所必需的。当前的研究涉及这些新发现的“助手”蛋白的性质以及MCO和Helper蛋白催化的化学。结果可用于阐明细菌如何将海水中的锰转化为矿物如何在排毒海水中发挥重要作用。这项工作影响了我们对科学多个领域的理解，包括海洋学，地质，生物学和生物化学。另一个广泛的影响是通过在包括高中在内的所有教育水平上包括学生。研究人员通过一项科学项目传播了从研究向公众获得的见解。一种涉及来自不同大学的两组的协作方法正在用于研究细菌锰MN（II）通过氧化和氧化锰的生产机制。来自Bacillus sp。 PL-12。通过溶解MN（II）的细菌氧化形成氧化锰（II）在水生和土壤环境中很重要，并且是全球MN循环中的关键途径，该途径通过许多酶的MN催化中心支持生命。该过程获得了增加的技术兴趣，因为它会导致高度反应性的纳米含量矿物质，这些矿物可以分解有机分子并吸附其他金属离子，从而控制许多有毒和基本元素的分布和生物利用度。使用化学，生物化学和生物物理学工具的跨学科工作被用来阐明MCO的锰氧化机制。这种氧化以及MNO2矿化的发生的生化机制是鲜为人知的。 在许多MN（II）氧化细菌的模型系统中，多杆氧化酶已被视为Mn（II）氧化的催化剂，包括来自Bacillus sp的最近纯化的Mn氧化酶复合物。 PL-12。 在这个项目中，来自芽孢杆菌的Mn氧化酶复合物的结构和机制。执行两个顺序的单电子氧化步骤，并阐明MNARESALISS MN。研究的特定目标是：1）表征MN氧化酶复合物的铜中心； 2）确定Mn氧化和氧气进入的过程； 3）表征在MNO2途径上形成的多核中间体； 4）描述活性复合物表达所需的辅助蛋白的作用； 5）阐明酶复合物和新兴氧化物的结构。 X射线晶体学和光谱方法正在与基本的生物化学技术结合使用以实现这些目标。

项目成果

Metallo-inhibition of Mnx, a bacterial manganese multicopper oxidase complex

Mnx（一种细菌锰多铜氧化酶复合物）的金属抑制

• DOI: 10.1016/j.jinorgbio.2021.111547
• 发表时间: 2021
• 期刊: Journal of Inorganic Biochemistry
• 影响因子: 3.9
• 作者: Soldatova, Alexandra V.;Fu, Wen;Romano, Christine A.;Tao, Lizhi;Casey, William H.;Britt, R. David;Tebo, Bradley M.;Spiro, Thomas G.
• 通讯作者: Spiro, Thomas G.