Structural and Functional Characterization of Cyanoglobin

蓝红蛋白的结构和功能表征

• 批准号: 0091182
• 负责人: Juliette Lecomte
• 金额: $ 30万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0091182&HistoricalAwards=false
• 关键词: Structural; Functional; Characterization; Cyanoglobin

Lecomte, Juliette0091182Cyanobacteria are oxygenic prokaryotes now known to produce a hemoglobin (Hb) related to certain bacterial and protozoan hemoglobins. Although in nitrogen-fixing cyanobacteria, hemoglobin appears to protect the nitrogenase complex from oxidative damage, in non-nitrogen-fixing cyanobacteria, such as Synechocystis sp. PCC 6803, the role of hemoglobin remains a mystery. The immediate goal of this project is to study the relationship between structure and reactivity in the hemoglobin of Synechocystis.Biophysical methods (NMR spectroscopy, optical spectroscopy, centrifugation, redox potential measurements) and biochemical methods (genetic manipulations, immunostaining techniques, phenotypic characterization, site-directed mutagenesis) will be applied to 1) investigate Synechocystis Hb in vivo; 2) determine its three-dimensional structure in solution; and 3) analyze the molecular determinants of its heme coordination and electrochemical properties. Comparison will be made to other hemoglobins to develop an atomic level understanding of heme reactivity in cyanobacterial globins and situate these proteins in their evolutionary context.The globin family of proteins has representatives in practically all kingdoms of organisms. In vertebrates, hemoglobins and myoglobins are responsible for the transport and storage of oxygen but in primitive organisms, the functional roles of globins include oxygen scavenging, delivery, sensing, and detoxification, and management of nitrosative stress. Cyanobacteria such as Synechocystis can be manipulated experimentally like other prokaryotes and subjected to genetic methods. Thus they are ideally suited for studies of ancient hemoglobins. A description of the function of cyanobacterial hemoglobins is expected to provide fundamental insight in the biochemistry of organisms essential in the global cycling of carbon and nitrogen.The project will serve as a support in teaching activities such as a biological chemistry course and an NMR course. It will provide excellent opportunities for undergraduate and graduate student training in biophysical and biochemical methods and foster multidisciplinary interactions.

Lecomte，Juliette 0091182蓝细菌是一种产氧原核生物，目前已知它能产生与某些细菌和原生动物血红蛋白相关的血红蛋白（Hb）。 虽然在固氮蓝藻中，血红蛋白似乎可以保护固氮酶复合体免受氧化损伤，但在非固氮蓝藻中，如集胞藻属PCC 6803，血红蛋白的作用仍然是一个谜。 该项目的近期目标是研究集胞藻血红蛋白的结构和反应性之间的关系。（NMR光谱法、光学光谱法、离心法、氧化还原电位测量）和生物化学方法（遗传操作、免疫染色技术、表型鉴定、定点突变）将被应用于1）在体内研究集胞藻Hb; 2）确定其在溶液中的三维结构; 3）分析其血红素配位和电化学性质的分子决定因素。 比较其他血红蛋白，以发展一个原子水平的理解，血红素反应蓝藻球蛋白和这些蛋白质在其进化context.The珠蛋白家族的蛋白质有代表性，在几乎所有的生物界。 在脊椎动物中，血红蛋白和肌红蛋白负责运输和储存氧，但在原始生物中，球蛋白的功能作用包括氧的清除，输送，传感和解毒，以及亚硝化应激的管理。 蓝细菌，如集胞藻，可以像其他原核生物一样进行实验操作，并进行遗传方法。 因此，它们非常适合研究古代血红蛋白。 通过对蓝藻血红蛋白的功能进行描述，可以对碳氮循环中的生物体的生物化学进行基本的认识。本项目将作为生物化学课程和NMR课程等教学活动的辅助。 它将为生物物理和生物化学方法的本科生和研究生培训提供极好的机会，并促进多学科的互动。