|Title||Modeling the catalytic site of vanadium bromoperoxidase: synthesis and structural characterization of intramolecularly H-bonded vanadium(V) oxoperoxo complexes, [VO(O(2))((NH)2pyg(2))]K and [VO(O(2))((BrNH)2pyg(2))]K.|
|Publication Type||Journal Article|
|Year of Publication||2002|
|Authors||Kimblin C, Bu X, Butler A|
|Date Published||2002 Jan 28|
|Keywords||Amines, Catalysis, Catalytic Domain, Chloride Peroxidase, Crystallography, X-Ray, Hydrogen Bonding, Lysine, Mitosporic Fungi, Models, Molecular, Molecular Conformation, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Peroxidases, Peroxides, Phaeophyta, Seaweed, Vanadium Compounds|
Vanadium haloperoxidases (VHPO) catalyze the peroxidative halogenation of organic substrates. Crystallographic studies suggest that hydrogen bonding from a lysine side chain to the vanadium(V)-bound peroxo group may facilitate oxidation of halides (Cl(-), Br(-), I(-)). A ligand with pendant NH(2) functionality, N-(2-pyridylmethyl-6-amino) iminodiacetic acid (H(2)(NH)2pyg(2).2HCl) has been designed to explore the effects that H-bonding from Lys may have on peroxide activation. The first structural characterization of VBrPO model complexes [VO(O(2))((NH)2pyg(2))]K and [VO(O(2))((BrNH)2pyg(2))]K which demonstrate direct intramolecular H-bonding between an amine functionality and V(V)-bound peroxide is reported. The distances between NH(2) proton and bound peroxo moiety [(d(N(1)-H.O): 2.637(4) A in [VO(O(2))((NH)()2pyg(2))]K, and 2.640(8) and 2.6919(8) A in [VO(O(2))((BrNH)2pyg(2))]K] are indicative of intramolecular H-bonding. The intramolecular H-bond strength in [VO(O(2))((BrNH)2pyg(2))](-) is estimated at 6 kcal/mol by (1)H NMR studies and demonstrates that the H-bond interaction is also significant in solution.
|Alternate Journal||Inorg Chem|