The Chloroplast ATP Synthase: Subunit Stucture and Function

叶绿体 ATP 合酶：亚基结构和功能

• 批准号: 8805048
• 负责人: Mark Richter
• 金额: --
• 依托单位: University of Kansas Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8805048&HistoricalAwards=false
• 关键词: Chloroplast; ATP; Synthase; Subunit; Stucture

The ATP synthase of mitochondria, chloroplasts and bacteria taps the energy of a transmembrane proton gradient to synthesize ATP. The mechanism of this important energy- conserving process is not understood in molecular terms. The enzyme is comprised of two portions, F0, which is an integral, membrane-spanning proton channel, and F1 which is peripheral to the membrane and contains the catalytic sites. Together F0 and F1 contain more than eight different protein subunits with a minimum of seventeen polypeptide chains. Three of the F1 subunits have been isolated in reconstitutively active forms from the chloroplast enzyme (CF1), and attempts to isolate the remaining two for use in reconstitution studies aimed at elucidating subunit structure-function relationships will be under taken. Other studies will aim at obtaining structural information for the B subunit which contains part or all of the catalytic site. Chemical modification with fluorescent and photoaffinity probes will be employed to map specific sites on the B subunit within the CF1 complex and to identify amino acid residues involved in, for example, nucleotide binding. Monoclonal antibodies will be used to identify sites of contact between the B subunit and other subunits of the ATP synthase. When plants capture sunlight they convert the radiant energy into chemical energy which supports the synthesis of plant constituents. The latter provide, directly or indirectly, the nutrients of animals, including man. The energy conversion process is complex and is catalyzed by a set of proteins in the chloroplast membrane. Several of these have been isolated and the PI wishes to isolate and characterize others so that eventually the whole complex can be reconstituted in a functional form.

线粒体、叶绿体和细菌的 ATP 合酶利用跨膜质子梯度的能量来合成 ATP。这一重要的能量守恒过程的机制尚无法从分子角度来理解。该酶由两部分组成，F0 是一个完整的跨膜质子通道，F1 位于膜的外围并包含催化位点。 F0 和 F1 总共包含超过八个不同的蛋白质亚基，至少有十七条多肽链。三个 F1 亚基已从叶绿体酶 (CF1) 中分离出具有重构活性的形式，并且将尝试分离其余两个用于旨在阐明亚基结构与功能关系的重构研究。其他研究旨在获得包含部分或全部催化位点的 B 亚基的结构信息。使用荧光和光亲和探针的化学修饰将用于绘制 CF1 复合物内 B 亚基上的特定位点，并鉴定参与核苷酸结合等的氨基酸残基。单克隆抗体将用于识别 ATP 合酶 B 亚基和其他亚基之间的接触位点。当植物捕获阳光时，它们会将辐射能转化为化学能，以支持植物成分的合成。后者直接或间接地为包括人类在内的动物提供营养。能量转换过程很复杂，由叶绿体膜中的一组蛋白质催化。其中一些已经被分离出来，PI 希望分离和描述其他的特征，以便最终可以以功能形式重建整个复合体。