Vanadium-Binding Ability of Nucleoside Diphosphate Kinase from the Vanadium-Rich Fan Worm, Pseudopotamilla occelata.
Polychaete fan worms and ascidians accumulate high levels of vanadium ions. Several vanadiumbinding proteins, known as vanabins, have been found in ascidians. However, no vanadium-binding factors have been isolated from the fan worm. In the present study, we sought to identify vanadiumbinding proteins in the branchial crown of the fan worm using immobilized metal ion affinity chromatography. A nucleoside diphosphate kinase (NDK) homolog was isolated and determined to be a vanadium-binding protein. Kinase activity of the NDK homologue, PoNDK, was suppressed by the addition of V(IV), but was unaffected by V(V). The effect of V(IV) on PoNDK precedes its activation by Mg(II). This is the first report to describe the relationship between NDK and V(IV). PoNDK is located in the epidermis of the branchial crown, and its distribution is very similar to that of vanadium. These results suggest that PoNDK is associated with vanadium accumulation and metabolism in P. occelata.
1 Marine Biological Laboratory, Graduate School of Science, Hiroshima University, Mukaishima-cho 2445, Onomichi city, Hiroshima 722-0073, Japan.
Nobuo
N
Yamaguchi
2 Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Japan.
Masafumi
M
Yoshinaga
3 National Institute of Technology and Evaluation, Kazusa-Kamatari 2-5-8, Kisarazu city, Chiba 292-0818, Japan.
Kei
K
Kamino
1 Marine Biological Laboratory, Graduate School of Science, Hiroshima University, Mukaishima-cho 2445, Onomichi city, Hiroshima 722-0073, Japan.|4 Department of Biological Science, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526, Japan.
Tatsuya
T
Ueki
D000818:Animals; D002352:Carrier Proteins; D002846:Chromatography, Affinity; D004817:Epidermis / Q000201:enzymology; D009701:Nucleoside-Diphosphate Kinase / Q000378:metabolism*; D011077:Polychaeta / Q000201:enzymology*; D014639:Vanadium / Q000378:metabolism*
D002352:Carrier Proteins; D014639:Vanadium; D009701:Nucleoside-Diphosphate Kinase
NDK; NDP kinase; metal accumulation; polychaete; vanadium