Highly selective ratiometric peptide-based chemosensors for zinc ions and applications in living cell imaging: a study for reasonable structure design.

Recently, fluorescent peptide-based chemosensors have been reported and used to detect series of metal ions in both aqueous solutions and living cells. In order to explore and indicate the structural regulations of "fluorophore-(His)-Pro-Gly-(His)-fluorophore (HL peptide sensor)", we predict the relationship between the number of histidine molecules and the coordination activity, as well as the preferred coordination site, through computational studies. L was modeled as showing the highest activity with the lowest calculated ΔE, and inner histidine residues bonding with the "Pro-Gly" core structure always provided essential coordination sites for zinc ions.