The role of hydroxyl group of tyrosine in copper(II) binding by His-analogs of oxytocin

► We described interaction between Cu(II) ions and histidine analogues of oxytocin. ► His-analogues of oxytocin are able to effective binding of Cu(II) ions. ► We used potentiometric measurements with spectroscopic studies. ► Theoretical calculation helped us revealed detailed structures of complexes.