9707382 Raghavan This work focuses on one of the major players of the cellular antigen processing machinery, the transporters associated with antigen processing (TAP). The TAP proteins are members of the ATP binding cassette (ABC) family of transmembrane transporters. The long term goal of this research is to gain insight into the mechanisms involved in substrate transport by ABC transporters. The TAP proteins will be investigated as the prototype transporter. Recombinant TAP proteins will be purified from insect cell membranes and reconstituted into artificial membranes to measure transport activities under strictly controlled conditions. The coupling between peptide and nucleotide binding by TAP will also be studied. Finally, soluble TAP fragments will be obtained for structural studies. A family of proteins called ABC transporters use the energy from ATP to transport various substances across cell membranes. This project uses biochemical and biophysical studies to understand the mechanism by which these transporters function.
