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モトハシ タケシ
MOTOHASHI TAKESHI
本橋 健 所属 京都産業大学 生命科学部 先端生命科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 1999/07 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Chloroplast thioredoxin mutants without active-site cysteines facilitate the reduction of the regulatory disulphide bridge on the gamma-subunit of chloroplast ATP synthase |
| 執筆形態 | その他 |
| 掲載誌名 | BIOCHEMICAL JOURNAL |
| 出版社・発行元 | PORTLAND PRESS LTD |
| 巻・号・頁 | 341(1),pp.157-163 |
| 著者・共著者 | MT Stumpp,K Motohashi,T Hisabori |
| 概要 | The activity of the chloroplast H+-ATPase (CF0CF1) is regulated by the proton electrochemical membrane potential and the reduction or the formation of the disulphide bridge on the gamma-subunit mediated by chloroplast thioredoxins (Trx). The latter regulation also applies to the water-soluble portion of CF0CF1 (CF1) and includes two successive steps, namely the binding of Trx to CF1 and the subsequent reduction or oxidation of CF1. To study this process thoroughly, a new expression system for spinach Trx-f and Trx-m was designed. In the presence of dithiothreitol (DTT) both forms of the expressed Trx could reduce the disulphide bridge on che gamma-subunit of CF1 and thus activate the ATPase. Trx mutants deficient in the internal, or both, cysteines of the active site were designed to study the details of the interaction. The Trx mutant proteins could still activate CF1-ATPase in the presence of DTT and they also increased the apparent affinity of CF1 for DTT, This implies that the binding of Trx to the CF1 gamma-subunit induces a conformational change facilitating the reduction of the disulphide bridge, and partially explains the high efficiency of Trx as a reductant in vitro. |
| DOI | 10.1042/0264-6021:3410157 |
| ISSN | 0264-6021/1470-8728 |
| NAID | 80011185865 |
| PMID | 10377257 |