Structure determination of membrane peptides of the Vacuolar ATP-ase complex by NMR spectroscopy

One of the characteristics of intracellular membrane compartments is that a difference exists between the pH of the lumen and of the cytoplasm. This pH difference is maintained by the Vacuolar ATPase (V-ATPase) protein complex. V-ATPases are present in osteoclast cells of the bone tissue and they also control calcium intake and uptake from bone. Several known bone diseases are caused by malfunction of the pH equilibrium and calcium homeostasis (for example osteoporosis and osteopetrosis).

The aim of the European consortium entitled  "Molecular Interactions of Vacuolar ATPase" is to find new therapeutic approaches against osteoporosis using the osteoclast V-ATPase as target. To produce possible inhibitors one needs to understand the structure and functional dynamics of this enzyme.

In this project, Afonso Duarte uses high-resolution multidimensional NMR spectroscopy and Molecular Dynamics to determine the structure of the V-ATPase complex present in the cell membrane. For this, the membrane protein of the V-ATPase complex is dissected into a range of peptides that are each analysed separately. Subsequently, modelling methods are applied to incorporate the determined peptide three-dimensional structures into the 3D model of the membrane protein. This strategy is based on findings of Yeagle et al. (Biochemistry 40, 11932-11937).

Contact for further information: Afonso Duarte or Marcus Hemminga or Carlo P.M. van Mierlo