Recently the intracellular domain (ICD ) of the Na+/H+ exchanger isoform 1 (NHE1), is a transmembrane protein, has been identified as an intrinsically disordered protein. NHE1/ICD regulates protein activity via binding of other proteins, kinases or calmodulin, as well as by interacting with the anionic phospholipids in the membrane. Although a specific lipid interaction domain (LID) in NHE1/ICD (named here after NHE1/LID) was identified, a detailed picture of the mechanism of interaction between the lipids in the membrane and NHE1/LID is still missing. We propose to collect structural data on NHE1/LID interaction with supported lipid bilayer (POPC and POPC/POPS) by means of Neutron Reflectometry. This data will complement our previous results and are aimed at characterizing the protein adsorption processes as well as at locating the adsorbed protein with respect to the membrane.