| Abstract |
The knowledge on the binding of vanadium ions and complexes to serum proteins and how vanadium might be transported in blood and up-taken by cells has received much attention during the last decade, particularly as far as the transport of (VO2+)-O-IV is concerned. In this work we revise and discuss some relevant aspects of previous research, namely the two main types of binding proposed for transport of (VO)-O-IV(carrier)(2) complexes. New results, obtained by circular dichroism (CD), EPR and gel electrophoresis, regarding the binding of vanadium to hTF in the oxidation states +5 and +3 are also presented. Namely, evidences for the binding of V-V-species to diferric-transferrin, designated by (Fe-III)(2)hTF, as well as to (Al-III)(2)hTF, are presented and discussed, the possibility of up-take of vanadate by cells through (Fe-III)(2)hTF endocytosis being suggested. It is also confirmed that V-III binds strongly to hTF, forming di-vanadium(III)-transferrin, designated by (V-III)(2)hTF, and gel electrophoresis experiments indicate that (V-III)(2)hTF corresponds to a closed conformation similar to (FeIII) 2hTF. (C) 2013 Elsevier B.V. All rights reserved. |
