By changing the Ultra High Vacuum (UHV) deposition method, classical sublimation versus electrospray ionization, one can tune the chemistry of a chiral dipeptide molecule (Gly-Pro, GP), when adsorbed on a Cu(110) surface, from anionic to zwitterionic, respectively. This chemical shift will influence the adsorption mode of the dipeptide; either in a three-point fashion in the case of anionic GP molecules with a strong interaction between the copper surface, both O atoms of the carboxylate moiety and the nitrogen atoms, while in the case of zwitterions GP, the adsorption mode relies on the sole interaction of 1 carboxylate oxygen atom. These different anchoring modes strongly modify the expression of surface 2D chirality and the supramolecular assemblies with two very distinct unit cells.