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ID 15044
本文ファイル
著者
Yoshinaga, Masafumi
Yamaguchi, Nobuo
Kamino, Kei
Michibata, Hitoshi
キーワード
Ascidian
Digestive system
Glutathione transferase
Metal accumulation
Vanadium
NDC
生物科学・一般生物学
抄録(英)
Some ascidians accumulate vanadium in vanadocytes, which are vanadium-containing blood cells, at high levels and with high selectivity. However, the mechanism and physiological significance of vanadium accumulation remain unknown. In this study, we isolated novel proteins with a striking homology to glutathione transferases (GSTs), designated AsGST-I and AsGST-II, from the digestive system of the vanadium-accumulating ascidian Ascidia sydneiensis samea, in which the digestive system is thought to be involved in vanadium uptake. Analysis of recombinant AsGST-I confirmed that AsGST-I has GST activity and forms a dimer, as do other GSTs. In addition, AsGST-I was revealed to have vanadium-binding activity, which has never been reported for GSTs isolated from other organisms. AsGST-I bound about 16 vanadium atoms as either V(IV) or V(V) per dimer, and the apparent dissociation constants for V(IV) and V(V) were 1.8 × 10-4 M and 1.2 × 10-4 M, respectively. Western blot analysis revealed that AsGSTs were expressed in the digestive system at exceptionally high levels, although they were localized in almost all organs and tissues examined. Considering these results, we postulate that AsGSTs play important roles in vanadium accumulation in the ascidian digestive system.
掲載誌名
Biochimica et Biophysica Acta - General Subjects
1760巻
3号
開始ページ
495
終了ページ
503
出版年月日
2006-03
出版者
Elsevier B.V.
ISSN
0304-4165
NCID
出版者DOI
PubMedID
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright (c) 2006 Elsevier B.V.
関連情報URL(IsVersionOf)
http://dx.doi.org/10.1016/j.bbagen.2006.01.008
部局名
理学研究科