ATCUN (aminoterminal Cu(II) and Ni(II)-binding) metallopeptides have been designed
and applied for different purposes comprising e.g. hydrogen evolution from water[1]
and antitumor drug treatment.[2] The redox activity of these complexes usually plays
a decisive role for such activities.
The Cu(II) complex of the most simple peptide motif Gly-Gly-His (GGH) has
surprisingly been proven to be almost redox inert.[3] In order to restore this redox
activity and also obtain additional functionalities, we incorporated fluorophores for
sensing Cu(II) ions[4] and artificial b-amino acids for influencing the chelate ring size
and thus stability, redox activity and even cytotoxicity of the Cu(II) peptides.[5]
Incorporation of N-heteroaromatics into the peptide ligand scaffold, e.g. a pyridine
moiety, led to an increased production of reactive oxygen species (ROS) from O2,
which were shown to be able to degrade DNA.[6] Conjugation with a targeting peptide
allowed selective cytotoxicity in cancer cells.