Bromoperoxidase activity of amavadin dissected: a DFT investigation.
Bromoperoxidase catalytic activity exerted by oxidated amavadin [V(HIDPA)2](-) (HIDPA = 2,2'-(hydroxyimino) dipropionate) in mono- and bis-protonated forms has been investigated by DFT. Possible reaction pathways for formation of peroxido/hydroperoxido complexes and subsequent bromide oxidation have been systematically dissected. The effect of increasing [H(+)] on catalytically active species and on halogenide oxidation has been also studied. Similarly to vanadium haloperoxidase (VHPO), the results point to a hydroperoxido amavadin adduct as the most reactive species toward bromide oxidation. However, comparison of the reactivity of amavadin and VHPO reveals also crucial differences in the catalytic mechanism of such natural V complexes.
Department of Biotechnology and Bioscience, Piazza della Scienza, 2, 20100 Milan, Italy. giuseppe.zampella@unimib.it luca.degioia@unimib.it.
Giuseppe
G
Zampella
Luca
L
Bertini
Luca
L
De Gioia
D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D006877:Hydroxamic Acids / Q000737:chemistry / Q000378:metabolism*; D007453:Iodide Peroxidase / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics; D014639:Vanadium / Q000737:chemistry
D006877:Hydroxamic Acids; C502921:N-hydroxyimino-2,2'-dipropionic acid; D014639:Vanadium; D010544:Peroxidases; C026195:bromide peroxidase; C414928:vanadium iodoperoxidase; D007453:Iodide Peroxidase; D000409:Alanine