Vanadium-binding protein in marine plankton from tropical south atlantic oceanWe investigated the role of plankton in the vanadium (V) cycle at Cabo Frio, Rio de Janeiro state, Brazil, a region with high V concentration in the atmospheric particles due to marine aerosol. The concentrations of V in plankton vary from 0.08 to 20.9 µg g-1 (zooplankton), 0.1 to 28.4 µg g-1 (phytoplankton > 64 µm) and < 0.0005 to 49.0 µg g-1 (small phytoplankton > 20 µm). The V speciation in biomolecules was performed by the use of two strategies: (i) coupling of size exclusion chromatography (SEC) for the fractionation of species with inductively coupled plasma mass spectrometry (ICP-MS) and (ii) with size exclusion anionic exchange chromatography with UV-Vis detector coupled to inductively coupled plasma mass spectrometry (SEC-AE-UV-Vis-ICP-MS). The results showed a single fraction containing V associated with a biomolecule in the range of 8 to 16 kDa, with isoeletric points above 8. The preliminary analyses using matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) do not permit to identify such biomolecule, considering the broader size range of the proteins obtained.
bioaccumulation; biogeochemistry; chemical ecology; HPLC-ICP-MS; metallothionein
