Data from: Conformational dynamics and asymmetry in multimodal inhibition of membrane-bound pyrophosphatases

Abstract Membrane-bound pyrophosphatases (mPPases) are homodimeric
proteins that hydrolyse pyrophosphate and pump H+/Na+ across membranes.
They are crucial for the virulence of protist pathogens, making them
attractive drug targets. In this study, we investigate the inhibitory
effects of seven distinct bisphosphonates against Thermotoga maritima
mPPase to explore their mode of action and assist in future small molecule
inhibitor development. We solved two structures of mPPase bound to the
inhibitors in the enzyme active sites and probed the conformational
dynamics of mPPase under multiple inhibitors and functionally relevant
conditions by double electron-electron resonance (DEER) spectroscopy. We
found that mPPase adopts distinct conformational equilibria in solution in
the presence of different inhibitors, including states consistent with
asymmetric binding in the active site (closed-open), but a symmetric
apo-like conformation on the periplasmic side (open-open). Combined with
solid-supported membrane-based electrophysiology recordings, this revealed
that during catalysis, one monomer of the dimer remains open, and Na+ can
only be pumped in a closed state. These results further support
symmetry-breaking across the membrane, consistent with
half-of-the-sites-reactivity.