权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

HEME C BIOSYNTHESIS IN DESULFOVIBRIO

脱硫弧菌中血红素 C 的生物合成

基本信息

批准号：
2810691
负责人：
RUSSELL TIMKOVICH
金额：
$ 10.73万
依托单位：
UNIVERSITY OF ALABAMA IN TUSCALOOSA
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-06-01 至 2003-05-31
项目状态：
已结题

项目摘要

The basic objective of this project is to determine how tetrapyrroles are biosynthesized in the strict anaerobe Desulfovibrio. Tetrapyrroles constitute an important class of biomolecules that function in diverse roles at the active site of many processes critical to cellular metabolism. As hemes, chlorophylls, vitamins, and Ni-cofactors, they are well known prosthetic groups essential for their catalytic properties. Desulfovibrio possess a high content of diverse electron transport hemoproteins. It has high tetrapyrrole biosynthesis activity in order to meet the requirements for these essential prosthetic groups, and therefore is an excellent microbial model system for the general area of tetrapyrrole production. Elucidation of the biosynthetic pathways to these hemes with an emphasis on characterizing the enzymes responsible for specific biotransformations of intermediates will provide fundamental knowledge toward understanding how high rates of tetrapyrrole biosynthesis can be achieved. The specific aims fall into two categories. Tetrapyrrole intermediates will be isolated and their chemical structures determined by a combination of optical, mass, and NMR spectroscopic techniques. Then enzymes responsible for the conversions of uroporphyrinogen into protoporphyrin IX and siroheme will be purified by conventional techniques of protein purification. Their physiochemical and enzymatic properties will be measured. Preliminary data to be discussed indicates that the Desulfovibrio biosynthetic system differs in several key ways from more conventional ones.

这个项目的基本目标是确定如何在严格的厌氧脱硫弧菌生物合成四吡咯。四吡咯构成一类重要的生物分子，其在对细胞代谢至关重要的许多过程的活性位点处发挥不同的作用。作为血红素、叶绿素、维生素和镍辅因子，它们是众所周知的催化性质所必需的辅基。脱硫弧菌具有高含量的多种电子传递血红素蛋白。它具有高的四吡咯生物合成活性，以满足这些必要的辅基的要求，因此是一个很好的微生物模型系统的一般领域的四吡咯生产。阐明这些血红素的生物合成途径，重点是表征负责中间体的特定生物转化的酶，将为了解四吡咯生物合成的高速率提供基础知识。具体目标分为两类。将分离四吡咯中间体，并通过光学、质谱和NMR光谱技术的组合确定其化学结构。然后，负责将尿卟啉原转化为原卟啉IX和西罗血红素的酶将通过常规的蛋白质纯化技术进行纯化。将测量它们的理化和酶性质。有待讨论的初步数据表明，脱硫弧菌生物合成系统在几个关键方面与更传统的系统不同。