Wydział Chemii

Mariola Kuczer

Agnieszka Matusiak

Elżbieta Czarniewska

Grzegorz Rosiński

Teresa Kowalik-Jankowska

2015

Polyhedron

85

151-160

10.1016/j.poly.2014.08.048

Naukowa

Angielski

Artykuł

The nineteenth amino acid peptide Neb-colloostatin SIVPLGLPVPIGPIVVGPR and its analogue with point mutation (P4A) were synthesized and their copper(II) complexes were studied by potentiometric, UV–Vis, circular dichroism (CD), and electron paramagnetic resonance (EPR) spectroscopic methods. The amine-N nitrogen atoms of serine residues were found to be the primary metal binding sites of both peptides. These binding modes provide the deprotonation and coordination of two amide nitrogens of the Neb-colloostatin and the formation of the 3N {NH₂,2N⁻,CO} complex at pH 7.5–8. The proline residue P⁴ is the breakpoint in the coordination of copper(II) ions and the 4N {NH₂,3N⁻} complex was not observed. At pH 8 the analogue (P4A) of Neb-colloostatin forms the copper(II) complex with 4N {NH₂,3N⁻} binding site. The potentiometric and spectroscopic results did not reveal the stabilizing role of the oxygen donors of side chains of seryl residues (S¹) in copper(II) complexes. At pH 8 the copper(II) ions change the secondary structures of both peptides in comparison to those without copper(II) ions. The induction of apoptosis in vivo in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH 7.4 was studied. The copper(II) complexes of Neb-colloostatin and its analogue exert stronger pro-apoptotic activity on insect hemocytes in comparison to those of peptides without metal ions.

copper(II) complexes, Neb-colloostatin, stability, structure, Apoptosis

http://dx.doi.org/10.1016/j.poly.2014.08.048

http://www.elsevier.com