cryo-EM structure of the human TNAP with an inhibitor

This proposal aims at solving the structure at high resolution of the human Tissue-nonspecific alkaline phosphatase (TNAP) dimer in complex with an inhibitor using Single Particle Analysis. This enzyme, mostly known to be involed in bone mineralization by its ability to hydrolyze inorganic pyrophosphate, can in fact dephosphorylate very different compounds to participate in very different physiological functions, which just begin to be unvealed. Since clinical trials have been recently launched to test the ability of TNAP inhibitors to block pathological calcification, the elucidation of TNAP structure, and the impact of its inhibition would be very useful. To date, only one recent study experimentally determined a 3D structure of human TNAP, but the enzyme was deglycosylated and analyzed without ligands [1]. In fact, no structural data exists for the TNAP protein in the presence of ligands (substrates, potential effectors, or inhibitors) and has never been studied by cryo-EM.