Model Complexes of the Active Site in Peptide Deformylase:  A New Family of Mononuclear N₂S−M(II) Complexes

Synthetic Analogues of Cysteinate‐Ligated Non‐Heme Iron and Non‐Corrinoid Cobalt Enzymes

“…241,242 Both Que and Girerd have shown that when ligated by nitrogen ligands, a side-on ferric peroxide will convert to end-on ferric hydroperoxide species upon protonation. 84,225,226,235,236,238 In both examples, the side-on peroxide (44 and 46; Figure 33 None of the synthetic complexes described above (44)(45)(46)(47) contain thiolate ligands. An obvious question in relation to SOR concerns how a thiolate sulfur ligand would affect H 2 O 2 formation and release.…”

“…This new class includes nitrile hydratases (NHases), [17][18][19][20][21][22][23][24][25][26][27][28] superoxide reductases (SORs), [29][30][31][32][33][34][35][36][37][38][39][40][41][42] and peptide deformylases (PDFs). [43][44][45] The active site structures of these enzymes are compared with that of N 2 O-ligated non-heme iron enzymes in Figure 1. Crystal structures are available for all three cysteinate-ligated non-heme iron enzymesnitrile hydratase (NHase), 25,26 superoxide reductase (SOR, vide infra), 34,40 and peptide deformylase (PDF).…”

“…An obvious question about the structure of this newer class of enzymes concerns the role that peptide amides and cysteinate sulfur ligand(s) might play in promoting function. The function of this new class of non-heme iron enzymes varies enormously from nitrile hydratation ( Figure 3) by nitrile hydratases (NHases), 22,23,[25][26][27][28]52 to the hydrolytic removal of a formyl "tag" by peptide deformylase (PDF), [44][45][46] to superoxide reduction ( Figure 3) by superoxide reductases (SORs). 33,34,42,53 Peptide amides have been shown to stabilize metal ions in higher oxidation states [54][55][56][57] and favor structures with lower coordination numbers.…”

Zinc Thiolate Reactivity toward Nitrogen Oxides: Insights into the Interaction of Zn2+ with S-Nitrosothiols and Implications for Nitric Oxide Synthase

“…35,36 Deprotonation of the ligand followed by ZnCl 2 addition afforded the chloride complex ZnPAThCl in decent yield (Scheme 1a). Structural parameters for ZnPAThCl match previously reported values.…”

Polymer supported synthesis of mixed ligand complexes

“…Mixed ligand complexes occur in the transition states of metal ion catalyzed reactions, and also the metal ions present in many biological systems are in the mixed ligand form 1–6. The synthesis and structural characterization of mixed ligand complexes is important and helpful for understanding the mechanism of catalysis and many biological processes.…”