このエントリーをはてなブックマークに追加
ID 24
file
creator
Adachi, Takahiro
Kawano, Sonoko
Aoshima, Masato
Yamaguchi, Nobuo
Kanamori, Kan
Michibata, Hitoshi
subject
Ascidian
Vanadium
Metal accumulation
NDC
Biology
abstract
Since the beginning of the last century, it has been known that ascidians accumulate high levels of a transition metal, vanadium, in their blood cells, although the mechanism for this curious biological function remains unknown. Recently, we identified three vanadium-binding proteins (vanabins), previously denoted as vanadium-associated proteins (Kanda et al., 1997), from the cytoplasm fraction of vanadium-containing blood cells (vanadocytes) of the vanadium-rich ascidian Ascidia sydneiensis samea. Here, we describe the cloning, expression, and analysis of the metal-binding ability of vanabins. Recombinant proteins of two independent but related vanabins, vanabin1 and vanabin2, bound to 10 and 20 vanadium(IV) ions with dissociation constants of 2.1 × 10-5 M and 2.3 × 10-5 M, respectively. The binding of vanadium(IV) to these vanabins was inhibited by the addition of copper(II) ions, but not by magnesium(II) or molybdate(VI) ions. Vanabins are the first proteins reported to show specific binding to vanadium ions; this should provide a clue to resolving the problem regarding the selective accumulation of vanadium in ascidians.
journal title
Biochimica et biophysica acta
volume
Volume 1626
start page
43
end page
50
date of issued
2003
publisher
Elsevier Science B.V.
issn
0167-4781
publisher doi
pubmed id
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) 2003 Elsevier Science B.V.
relation is version of URL
http://dx.doi.org/10.1016/S0167-4781(03)00036-8
department
Graduate School of Science