SYNTHETIC PROBES OF HEME AND CHLOROPHYLL BIOCHEMISTRY

血红素和叶绿素生物化学的合成探针

• 批准号: 3280389
• 负责人: ANDREW D HAMILTON
• 金额: $ 13.06万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1990-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3280389
• 关键词: binding proteins; chemical models; chemical structure function; chlorin; chlorophyll; chromophore; dimer; electrochemistry; electron transport; enzyme model; fluorescence; heme; microorganism metabolism; photosynthesis; porphyrins; tetrapyrroles

This proposal concerns the preparation and study of synthetic models of heme- and chlorophyll- containing proteins. In particular, we plan to investigate the role of specifically ordered aggregates to tetrapyrroles in such key biological processes as photosynthesis and electron transfer. We have developed a new strategy for the construction of covalently-linked multiple tetrapyrroles with different distances and orientations between the rings. In this application we propose to extend this approach to model more closely the structure of multiple tetrapyrrole sites in biology. Our primary targets are tetrameric and hexameric analogs of the known structure of bacterial photosynthetic reaction centers. These models will, respectively, contain the dimer-bis(monomer) and dimer-bis(monomer)-bis(non-metallated monomer) structure of the reaction centers. By varying the synthesis used we will be able to generate a series of compounds with different although related structures. Thorough physical investigation of these derivatives, using electrochemical, fluoresence and picosecond optical techniques, will provide details of the photoinduced electron transfer and charge separation processes occurring between the pigments. This will allow us, for the first time to probe the effect of chromophore distance and orientation on key aspects of the photosynthetic process. We will also construct simple linear arrays of photoactive redox partners as comparisons to the biomimetic models. In later model compounds we will introduce chlorin and bacteriochlorin macrocycles in place of the porphyrin building blocks. Model studies of this type will lead to an understanding of protein control of reactivity that is crucial for solving the medical problems associated with tetrapyrrole biochemistry.

本提案涉及合成材料的制备和研究