ChemInform Abstract: The Coordination Chemistry of Vanadium as Related to Its Biological Functions

Abstract

Abstract The binding of vanadium to protein side-chains such as provided by tyrosinate, serinate, aspartate, glutamate, cysteinate, methionine and histidine is modelled by complexes with ligand sets containing phenolate, alkoxide, carboxylate, thiolate, thioether and enamine functions. The complexes mimic possible intermediates and structural motifs of the coordination environment of vanadium in vanadium–nitrogenase, vanadate-dependent haloperoxidases, the interaction with phosphorylation enzymes, and the redox-interaction with cysteinyl residues. The solid state investigations are supplemented by solution studies on vanadate–dipeptide and vanadate–adenosine systems, based on combined 51 V-NMR and potentiometric measurements. Model reactions for the function of haloperoxidases and vanadium–nitrogenase (including the alkyne–reductase and isonitrile–reductase/ligase activities) are described, and the impact of these investigations for corresponding in vitro applications is dealt with. The relevance of catecholatovanadium complexes for the accumulation of vanadium by ascidians is also addressed.