High stability and biological activity of the copper(II) complexes of alloferon 1 analogues containing tryptophan.

High stability and biological activity of the copper(II) complexes of alloferon 1 analogues containing tryptophan.
J Inorg Biochem. 2016 Jul 9;
Authors: Kadej A, Kuczer M, Czarniewska E, Urbański A, Rosiński G, Kowalik-Jankowska T
Abstract
Copper(II) complex formation processes between the alloferon 1 (Allo1) (HGVSGHGQHGVHG) analogues where the tryptophan residue is introducing in the place His residue H1W, H6W, H9W and H12W have been studied by potentiometric, UV-visible, CD and EPR spectroscopic, and MS methods. For all analogues of alloferon 1 complex speciation have been obtained for a 1:1 metal-to-ligand molar ratio and 2:1 of H1W because of precipitation at higher (2:1, 3:1 and 4:1) ratios. At physiological pH7.4 and a 1:1 metal-to-ligand molar ratio the tryptophan analogues of alloferon 1 form the CuH-1L and/or CuH-2L complexes with the 4N binding mode. The introduction of tryptophan in place of histidine residues changes the distribution diagram of the complexes formed with the change of pH and their stability constants compared to the respective substituted alanine analogues of alloferon 1. The CuH-1L, CuH-2L and CuH-3L complexes of the tryptophan analogues are more stable from 1 to 5 log units in comparison to those of the alanine analogues. This stabilization of the complexes may result from cation(Cu(II))-π and indole/imidazole ring interactions. The induction of apoptosis in vivo, in Tenebrio molitor cells by the liga...

Source: Journal of Inorganic Biochemistry - July 8, 2016 Category: Biochemistry Authors: Kadej A, Kuczer M, Czarniewska E, Urbański A, Rosiński G, Kowalik-Jankowska T Tags: J Inorg Biochem Source Type: research