Novel short-chain analogues of somatostatin as ligands for Cu(II) ions. Role of the metal ion binding on the spatial structure of the ligand

In this paper we present the studies on coordination abilities of two short-chain analogues of somatostatin with free N-terminal and protected amino group towards copper (II) ions. The octreotide is the most popular analogue of the somatostatin (peptide hormone) used in medicine. Somatostatin analogues are used in diagnosis and treatment of the neuroendocrine tumors. Both analyzed analogues are characterized by the presence of two His instead of Cys residues in characteristic fragment of native peptide. We characterize coordination abilities of the ligands using potentiometric and spectroscopic methods. His-analogues of somatostatin are effective ligands for copper (II) ions. Both peptides are able to form the complexes with the cyclic structure.

The comparison of the calculated structures of the Cys-analogue of analyzed peptide and cyclic, CuL complex of Ac-[His2,7]P2.Figure optionsDownload as PowerPoint slideHighlights
► Two short-chain analogues of somatostatin with copper(II) ions were analyzed.
► Both analogues are characterized by the presence two His instead of Cys residues.
► Coordination abilities of the ligands was obtained.
► His-analogues of somatostatin are effective ligands for metal ions.
► Potentiometric and spectroscopic methods were used.