Physiochemical Study on Highly Selective Accumulation of Vanadium Ions by Ascidians

海鞘高选择性积累钒离子的理化研究

• 批准号: 09440278
• 负责人: MICHIBATA Hitoshi
• 金额: $ 2.56万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440278/
• 关键词: Protochordates; Metal Accumulation; Redox; Vanadium; Vacuole; pH; Recombinant Proteins; Monoclonal Antibody; 濃縮機構; 還元機構; ペントースリン酸回路

A lot is known about the vanadium in ascidians, which are also known as tunicates or sea squirts. For example, the concentration of vanadium attains 350 mMin the blood cells of Ascidia gemmata belonging to the suborder Phlebobranchia, which is l0^7times higher than the concentration in sea water among approximately ten types of blood. cells, signet ring cells are true vanadocytes, vanadium-containing blood cells, almost all vanadium is reduced to the +3 oxidation state (V^<III>) via the +4 oxidation state (V^<IV>) and stored in vacuoles of vanadocytes, although vanadium is in the +5 oxidation state (V^V) in seawater.We have revealed by the research project followings : a vanadium-associated protein (VAP) extracted from the blood cells of A.sydneiensis sames was revealed to contain 16 atoms of vanadium per a mol ; the same antigen recognized with a polyclonal antibody against VAP was detected in the precipitated proteins of the polychaete Pseudopotamilla occelata which was the first animal revealed to contain high levels of vanadium besides ascidians ; apo-VAP, VAP removed vanadium, was found to bind 10 atoms of vanadium ; the nucleotide sequences of cDNAs encoding 12.5 kDa and 15 kDa of VAPs are revealed ; a fusion protein was isolated from E.coil transfected with plasmid vector expressing VAPs genes ; a monoclonal antibody specific to vacuolar membrane of vanadocytes was prepared ; G6PDH, 6PGDH, and transketolase in the pentose phosphate pathway and glycogen phosphorylase were found to be in the cytoplasm of vanadocytes ; NADPH was revealed to reduce V^V-EDTA to V^<IV>-EDTA.

人们对海鞘类（也称为被囊类动物或海鞘类）中的钒了解很多。例如，属于白鳃亚目的Ascidia gemmata的血细胞中钒的浓度达到350mMin，大约是十种血液中的海水浓度的10^7倍。印戒细胞是真正的钒细胞，即含钒的血细胞，几乎所有的钒都通过+4氧化态（V^<IV>）还原为+3氧化态（V^<III>）并储存在钒细胞的液泡中，尽管钒在海水中处于+5氧化态（V^V）。我们通过研究项目揭示了以下内容： 从悉尼猕猴桃血细胞中提取的钒相关蛋白（VAP）被发现每摩尔含有 16 个钒原子；在多毛类 Pseudopotamilla occelata 的沉淀蛋白中检测到与 VAP 多克隆抗体识别的相同抗原，该动物是除海鞘之外第一个被发现含有高水平钒的动物； apo-VAP，VAP去除了钒，发现结合了10个钒原子；揭示了编码 12.5 kDa 和 15 kDa VAP 的 cDNA 的核苷酸序列；从表达VAPs基因的质粒载体转染的大肠杆菌中分离得到融合蛋白；制备了针对钒细胞空泡膜的特异性单克隆抗体；钒细胞胞质中发现G6PDH、6PGDH、戊糖磷酸途径中的转酮醇酶和糖原磷酸化酶；揭示NADPH将V ^ V -EDTA还原为V ^ IV -EDTA。

项目成果

Michibata,H.: "The accumulation mechanism of vanadium by ascidians.In "Proc.Symp.Chemistry,Biochemistry and Therapeutic Applications of Vanadium Compounds." Edited by Tracey,A.and Crans,D.C.,Am.Chem.Soc.(in press), (1997)

Michibata, H.：“海鞘对钒的积累机制。在“Proc.Symp.化学、钒化合物的生物化学和治疗应用”中。由 Tracey,A. 和 Crans,D.C. 编辑，Am.Chem.Soc.（in

Michibata, H.: "Exploring the mystery of vanadocytes, cells specialized for the vanadium accumulation in ascidians" Seibutsubutsuri. 37. 315-320 (1997)

Michibata, H.：“探索钒细胞的奥秘，钒细胞是海鞘中专门积累钒的细胞”Seibutsubutsuri。

Uyama, T.: "A 100-kDa antigen recognized by a newly prepared monoclonal antibody specific to the vanadocytes of the vanadium-rich ascidian, Ascidia sydneiensis samea, is glycogen phosphorylase." Zool.Sci.15. 815-821 (1998)

Uyama, T.：“新制备的单克隆抗体可识别富含钒的海鞘（Ascidia sydneiensis Samea）的钒细胞特异的 100 kDa 抗原，它是糖原磷酸化酶。”

Uyama,T.: "Glucose-6-phosphate dehydrogenase in the pentose phosphate pathway is.Iocalized in vanadocytes of the vanadium-rich ascidian,Ascidia sydneiensis samea." Zool.Sci.15. 441-446 (1998)

Uyama,T.：“戊糖磷酸途径中的葡萄糖-6-磷酸脱氢酶是。定位于富含钒的海鞘（Ascidia sydneiensis Samea）的钒细胞中。”

Nose, Y.: "Specific increase in the number of vanadium-accumulating blood cells by some ionophores and inhibitors of proton-ATPases in the ascidian, Ascidia sydneiensis samea." Zool.Sci.14. 199-204 (1997)

Nose, Y.：“海鞘（Ascidia sydneiensis Samea）中的一些离子载体和质子-ATP 酶抑制剂可以明显增加钒积累的血细胞数量。”