Impact of the spatial distribution of positive charges on the catalytic activity of NiSOD bioinspired complexes
Abstract
In order to mitigate superoxide-induced damage, cells rely on superoxide dismutases (SODs), a family of metalloenzymes that catalyze the dismutation of superoxide. These enzymes display a positively-charged substrate entrance channel for superoxide guidance to the active metal center. ATCUN-like Ni(II) complexes have been shown to mimic NiSOD effectively and benefit from versatile peptide structures, which are ideal for introducing positive charges through arginine residues at various positions to modulate catalytic properties. We describe here five novel ATCUN-like Ni(II) complexes, with arginines at various positions in close proximity to the metal center. All the peptides form monometallic square planar Ni(II) complexes in water at pH 7.4, with either a N2S2 coordination (S-series) or an equilibrium between N2S2 and N3S1 coordination modes (N/S-series). The S-series demonstrates a clear beneficial effect of the charge increase from − 2 to + 2 on the pseudo-first order catalytic constant. Furthermore, the data obtained for the N/S complexes demonstrate that introducing an arginine residue in the central position of the ATCUN-like motif does not enhance activity, but actually impedes catalysis. These findings show that both the distance of the charged residues from the metal center and their positioning in space are of prime importance.
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BibTeX
@article{guinard2026impact,
title = {{Impact of the spatial distribution of positive charges on the catalytic activity of NiSOD bioinspired complexes}},
author = {Pawel Guinard and Jacques Pécaut and Alan Le-Goff and Carole Duboc and Pascale Delangle and Sarah Hostachy},
journal = {Journal of Biological Inorganic Chemistry},
year = {2026},
month = may,
doi = {10.1007/s00775-026-02150-3},
url = {https://hal.science/hal-05787416v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Impact of the spatial distribution of positive charges on the catalytic activity of NiSOD bioinspired complexes
AU - Pawel Guinard
AU - Jacques Pécaut
AU - Alan Le-Goff
AU - Carole Duboc
AU - Pascale Delangle
AU - Sarah Hostachy
PY - 2026
DA - 2026/05/19
JO - Journal of Biological Inorganic Chemistry
DO - 10.1007/s00775-026-02150-3
UR - https://hal.science/hal-05787416v1
AB - In order to mitigate superoxide-induced damage, cells rely on superoxide dismutases (SODs), a family of metalloenzymes that catalyze the dismutation of superoxide. These enzymes display a positively-charged substrate entrance channel for superoxide guidance to the active metal center. ATCUN-like Ni(II) complexes have been shown to mimic NiSOD effectively and benefit from versatile peptide structures, which are ideal for introducing positive charges through arginine residues at various positions to modulate catalytic properties. We describe here five novel ATCUN-like Ni(II) complexes, with arginines at various positions in close proximity to the metal center. All the peptides form monometallic square planar Ni(II) complexes in water at pH 7.4, with either a N2S2 coordination (S-series) or an equilibrium between N2S2 and N3S1 coordination modes (N/S-series). The S-series demonstrates a clear beneficial effect of the charge increase from − 2 to + 2 on the pseudo-first order catalytic constant. Furthermore, the data obtained for the N/S complexes demonstrate that introducing an arginine residue in the central position of the ATCUN-like motif does not enhance activity, but actually impedes catalysis. These findings show that both the distance of the charged residues from the metal center and their positioning in space are of prime importance.
SN - 0949-8257
SN - 1432-1327
ER -