Wydział Chemii

Agnieszka Matusiak

Mariola Kuczer

Elżbieta Czarniewska

Grzegorz Rosiński

Teresa Kowalik-Jankowska

2014

Journal of Inorganic Biochemistry

138

99-113

10.1016/j.jinorgbio.2014.05.012

Naukowa

Angielski

Artykuł

Mono- and polynuclear copper(II) complexes of the alloferon 1 with point mutations (H1A) A¹GVSGH⁶GQH⁹GVH¹²G (Allo1A) and (H9A) H¹GVSGH⁶GQA⁹GVH¹²G (Allo9A) have been studied by potentiometric, UV–visible, CD, EPR spectroscopic and mass spectrometry (MS) methods. To obtain a complete complex speciation different metal-to-ligand molar ratios ranging from 1:1 to 4:1 for Allo1A and to 3:1 for Allo9A were studied. The presence of the His residue in first position of the peptide chain changes the coordination abilities of the Allo9A peptide in comparison to that of the Allo1A. Imidazole-N3 atom of N-terminal His residue of the Allo9A peptide forms stable 6-membered chelate with the terminal amino group. Furthermore, the presence of two additional histidine residues in the Allo9A peptide (H⁶,H¹²) leads to the formation of the CuL complex with 4N {NH₂,N_Im–H¹,N_Im–H⁶,N_Im–H¹²} binding site in wide pH range (5–8). For the Cu(II)–Allo1A system, the results demonstrated that at physiological pH 7.4 the predominant complex the CuH_− 1L consists of the 3N {NH₂,N⁻,CO,N_Im} coordination mode. The inductions of phenoloxidase activity and apoptosis in vivo in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH 7.4 were studied. The Allo1A, Allo1K peptides and their copper(II) complexes displayed the lowest hemocytotoxic activity while the most active was the Cu(II)–Allo9A complex formed at pH 7.4. The results may suggest that the N-terminal-His¹ and His⁶ residues may be more important for their proapoptotic properties in insects than those at positions 9 and 12 in the peptide chain.

Alloferon, Copper, Biological activity, Mono- and polynuclear complexes, Apoptosis

http://dx.doi.org/10.1016/j.jinorgbio.2014.05.012

http://www.elsevier.com