The F1 ATPase is large, membrane-associated protein which links an equilibrium reaction between the two adenine nucleotides, adenosine triphosphate and adenosine diphosphate, and the translocation of protons across the membrane. Thus, with a suitable proton electrochemical potential difference across the membrane it can drive the net synthesis of adenosine triphosphate. This system will be studied by phosphorous solid state nuclear magnetic resonance. Attempts will be made to detect intermediates in the reaction and to measure rates of reaction. Attempts will also be made to determine distances between a bound metal ion required for reactions (manganese will be substituted for magnesium) and the phosphate groups of the nucleotide. The overall goal of this work is to define the structure and kinetics of the active site of the enzyme in situ; previous studies have relied on extraction techniques which may not reflect the true concentrations of reactants on the enzyme itself. Longer term aims of this study are to extend the NMR experiments and measure the proximity of specific amino acid residues on the protein to the bound adenine nucleotides.
