Brings about the iodination of a range of organic molecules, forming stable C-I bonds. The enzymes of this group contain vanadium (V) bound to the active centre.
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RH + I- + H2O2 + H+ = RI + 2 H2O
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
the catalytic cycle imposes changes in the coordination geometry of the vanadium to accommodate the peroxidovanadium(V) intermediate in an environment of as a distorted square pyramidal geometry. During the catalytic cycle, this intermediate converts to a trigonal bipyramidal intermediate before losing the halogen and forming a tetrahedral vanadium-protein intermediate. The catalysis is facilitated by a proton-relay system supplied by the second sphere coordination environment, and the changes in the coordination environment of the vanadium(V) making this process unique among protein catalyzed processes. The active site is very tightly regulated with only minor changes in the coordination geometry. The coordination geometry in the protein structures deviates from that found for both small molecules crystallized in the absence of protein and the reported functional small molecule model compounds. The catalytic mechanism for oxidation of organic substrates catalyzed by haloperoxidases does not change the oxidation state of the vanadium(V) although the vanadium is present as protein bound intermediate with a coordination number altering from four to six
required vanadium as a transition metal ion that readily converts among oxidations states has the potential to support catalytic processes through oxidation/reduction chemistry as well as hydrolytic chemistry. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
vanadium-dependent haloperoxidases (VPXOs) are a class of enzymes that catalyze selective oxidation reactions for which vanadium is an essential cofactor converting halides to form halogenated organic products and water. These enzymes include chloroperoxidase and bromoperoxidase, which have very different protein sequences and sizes, but regardless the coordination environment of the active sites is constant. Coordination chemistry of the vanadium(V) center in the different vanadium-haloperoxidases, overview
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CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
to 1.8 A resolution, revealing a monomeric structure mainly folded into alpha-helices. The vanadate binding site is strictly conserved with the fungal VCPO active site. Specific amino acids and the associated hydrogen bonding network around the vanadate center are essential for the catalytic properties and also the iodide specificity
iodoperoxidase PcI is inactivated by extensive diafiltration using a Centricon-30 (Amicon) device against 100 mM citrate/phosphate pH 3.8 buffer in the presence of 1 mM EDTA, followed by a second diafiltration with 50 mM Tris-HCl (pH 9.0), reactivation by vanadium, iodoperoxidase PcI
iodoperoxidase PcII is inactivated by extensive diafiltration using a Centricon-30 (Amicon) device against 100 mM citrate/phosphate pH 3.8 buffer in the presence of 1 mM EDTA, followed by a second diafiltration with 50 mM Tris-HCl (pH 9.0), reactivation by vanadium, iodoperoxidase PcI
for iodoperoxidase activity measurement, the triiodide assay should only be used for qualitative applications. A quantitative spectrophotometric assay is based on the iodination of thymol blue but can only be used in the pH range 7-8
to detect activity on polyacrylamide gels or in cross sections of algal part, o-dianisidine may be used. The probes are first incubated in a buffered solution containing 100 mM KBr or 100 mM KI, and 10 mM o-dianisidine, and the staining is started by addition of 2 mM H2O2. The formed HOBr or HOI will oxidize the organic dye resulting in polymerization and formation of a brown precipitate
Fournier, J.B.; Rebuffet, E.; Delage, L.; Grijol, R.; Meslet-Cladiere, L.; Rzonca, J.; Potin, P.; Michel, G.; Czjzek, M.; Leblanc, C.
The vanadium iodoperoxidase from the marine flavobacteriaceae species Zobellia galactanivorans reveals novel molecular and evolutionary features of halide specificity in the vanadium haloperoxidase enzyme family