PREPARATION AND LOCALIZATION OF A MONOCLONAL-ANTIBODY AGAINST A VANADIUM-ASSOCIATED PROTEIN EXTRACTED FROM THE BLOOD-CELLS OF THE VANADIUM-RICH ASCIDIAN, ASCIDIA-SYDNEIENSIS-SAMEA

Ascidians are known to accumulate high levels of vanadium in their blo od cells. Recently, we found a vanadium-associated protein (VAP) in bl ood cells of a vanadium-rich ascidian, Ascidia sydneiensis samea. In t his paper, we raised a monoclonal antibody against VAP, designated F8D H. Immunoblot analysis showed that F8DH recognized 2 related peptides of 15 kDa and 16 kDa of VAP. Using F8DH, VAP was shown to be in the cy toplasm of vanadocytes and compartment cells, both of which were repor ted to contain vanadium. F8DH also stained the vanadocytes distributed in the connective tissues around the alimentary canal, suggesting tha t vanadocytes in the connective tissue contained VAP. Furthermore, blo od cells of 3 different species of ascidian having high levels of vana dium, A. sydneiensis samea, A. ahodori, and Ciona intestinalis, showed reactivity of F8DH but little reactivity was observed in 2 species ha ving less vanadium, Halocynthia roretzi and Pyura michaelseni, suggest ing that VAP recognized by F8DH is a common protein in vanadium-rich a scidians.