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Solution Structure of a Functional Biomimetic and Mechanistic Implications for Nickel Superoxide Dismutases
Author(s) -
Schmidt Matthias,
Zahn Stefan,
Carella Michela,
Ohlenschläger Oliver,
Görlach Matthias,
Kothe Erika,
Weston James
Publication year - 2008
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200800017
Subject(s) - chemistry , superoxide dismutase , nickel , stereochemistry , enzyme , peptide , proline , amino acid , combinatorial chemistry , ligand (biochemistry) , biochemistry , organic chemistry , receptor
The nickel complex of a synthetic nonapeptide (HCDLPCFVY‐NH 2 ) is capable of catalytically disproportionating O 2 .− and is thus a functional biomimetic for nickel superoxide dismutases. This represents a simplification as compared to a NiSOD “maquette” that is based on a dodecapeptide that was recently reported [ Inorg. Chem. 2006 , 45 , 2358]. The 3D solution structure reveals that the first six residues form a stable macrocyclic structure with a preformed binding site for Ni II . Proline 5 exhibits a trans peptide linkage in the biomimetic and a cis conformation in NiSOD enzymes. DFT calculations reveal the source of this preference. Mechanistic consequences for the mode of action (identity of the fifth ligand) are discussed. The SOD activity is compared to enzymatic systems, and selected modifications allowed the biomimetic to be reduced to a functional minimal motif of only six amino acids (ACAAPC‐NH 2 ).