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ヨコヤマ ケン
YOKOYAMA KEN
横山 謙 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 | 1990 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Thermus thermophilus membrane-associated ATPase. Indication of a eubacterial V-type ATPase |
| 執筆形態 | その他 |
| 掲載誌名 | Journal of Biological Chemistry |
| 巻・号・頁 | 265(35),pp.21946-21950 |
| 著者・共著者 | K. Yokoyama,T. Oshima,M. Yoshida |
| 概要 | An ATPase with M(r) of 360,000 was purified from plasma membranes of a thermophilic eubacterium Thermas thermophilus, and was characterized. ATP hydrolytic activity of the purified enzyme was extremely low, 0.07 μmol of P(i) released mg-1 min-1 and it was stimulated up to 30-fold by bisulfite. The following properties of the enzyme indicate that it is not a usual F1-ATPase but that it belongs to the V-type ATPase family, another class of ATPases found in membranes of archaebacteria and eukaryotic endomembranes. Among its four kinds of subunits with approximate M(r) values of 66,000 (α), 55,000 (β), 30,000 (γ), and 12,000 (δ), the α subunit had a similar molecular size to the catalytic subunits of the V-type ATPases but was significantly larger than the α subunit of F1-ATPases. ATP hydrolytic activity was not affected by azide, an inhibitor of F1-ATPases, but was inhibited by nitrate, an inhibitor of the V-type ATPase. N-terminal amino acid sequences determined for the purified α and β subunits showed much higher similarity to those of the V-type ATPases than those of F1-ATPases. Thus the distribution of the V-type ATPase in the prokaryotic kingdom may not be restricted to archaebacteria. |
| ISSN | 0021-9258 |
| PMID | 2147690 |