Copper(II) complexes of alloferon 1 with point mutations (H1A) and (H9A) stability structure and biological activity

Copper(II) complexes of terminally free alloferon peptide mutants containing two different histidyl (H1 and H6 or H9 or H12) binding sites Structure Stability and Biological Activity

“…The differences in the d-d transition energies for CuHL complexes of the systems studied result from different concentration and the presence several overlapping species in solution. The logK* values for the CuHL complexes (−3.94 to −4.06, Table 4) are consistent with the values obtained for the complexes with histamine in the 2 N {NH 2 ,N Im -H 1 } coordination mode [23][24][25]56]. For the peptides containing His residue at N-terminal position of the peptide chain with increasing pH, the formation of dimeric species has been observed (His-Gly-Gly [57][58][59] and His-Ser-Asp-Gly-Ile-NH 2 [53]).…”

“…5d) [47]. It should be mentioned that similar spectroscopic parameters were observed for the CuH −3 L and CuH − 4 L complexes of the Cu(II)-H12A [24] and the Cu(II)-H9A [25] systems. Therefore, it is likely that the histidine residue at the sixth position of the peptide chain interacts axially with the copper(II) ions.…”

“…We also observed that the pH 7.4 is optimal for heart activity of this beetle in vivo conditions. The pH of MOPS buffer was the same as physiological solution applied by us in previous studies [24,25].…”

“…The copper(II) coordination abilities [23] and apoptosis activity of alloferon 1 and its analogues with point mutations H6A, H12A [24] and H1A, H9A [25] were determined. The induction of apoptosis in vivo in Tenebrio molitor by the ligands and their copper(II) complexes at pH 7.4 showed that the most active are the Cu(II)-H9A and Cu(II)-H12A complexes formed at this pH with {NH 2 ,N Im -H 1 ,N Im 6 ,N Im 9 or 12 } binding sites.…”

“…Moreover, the effects of the alloferon mutants H9A/H12A, H6A/H12A, H6A/H9A and their Cu(II) complexes on the phenyloxidase enzyme activity in T. molitor have been studied. The coordination abilities and biological activities of the alloferon analogues studied are compared to those of the alloferon mutants containing three histidine residues and alloferon 1 [24,25].…”