Interaction of [VO₂(MA)₂]⁻ with model membranes: relevance to insulin enhancing effects of BMOV and its oxidized form

Abstract

Anti-diabetic vanadium-containing compounds and salts reportedly have effects on the overall organization of the cytoskeleton and the plasma membrane of cells. For ligand-mediated signaling, appropriate cytoskeletal and membrane lipid organization is essential for down-stream signaling to occur. A number of vanadium-containing compounds and salts are of interest because of their effects on these important cellular structures. Promising results in regulating diabetic symptoms such as glucose and lipid metabolism have been shown to result from the use of various anti-diabetic vanadium drugs. Their effects on the cytoskeleton and plasma membrane are reviewed Chapter I. Due to the importance of membrane interactions of vanadium-containing compounds with insulin-enhancing activity in ligand-mediated signaling, two simple membrane model systems were used to investigate the interactions of an oxidized metabolite of bis(maltolato)oxovanadium(IV) with model lipid interfaces. Studies were carried out using multinuclear NMR spectroscopy with a focus on 1H NMR techniques. In Chapter II we demonstrate that there were slight changes in 1H NMR spectra indicating that this BMOV metabolite was able to penetrate the lipid interface. These findings are important in understanding the pharmacologic mechanism of action of this anti-diabetic compound in cells and intact animals.