Vanadium dependent peroxidase

Rehder, D., W. Priebsch, and M. von Oeynhausen. 1989. Structural characterization of a monomer V(V) and a (2+4)-nuclear V(IV)V(V) carboxylato complex. Models for vanadium-dependent peroxidases. Angewandte Chemie 28 1221-1235. 

Only recently the isolation of a vanadium dependent peroxidase from algae (ref. 2), and a vanadium nitrogenase from Acotobacter (ref. 3) has changed this view. 

Vilter H (1984) Peroxidase from Phaeophyceae a vanadium (V)-dependent peroxidase from Ascophyllum nodosum. Phytochem 23 1387-1390. 

Enzymes requiring vanadium for catalytic activity. Perhaps the best studied of these are the vanadium-dependent nitrogenases [EC 1.18.6.1]. Other vanadium-dependent enzymes include vanadium haloperoxidase, vanadium chloroperoxidase, and vanadium bromoper-oxidase. In the vanadium chloroperoxidase and bromo-peroxidase reactions, the vanadium(V) is coordinated in a trigonal bipyramidal site to a histidyl residue, three nonprotein oxygens, and, presumably, to a hydroxide. 

Many peroxovanadates have potent insulin-mimetic properties [1,2]. Apparently, this functionality derives from the ability of these compounds to rapidly oxidize the active site thiols found in the group of protein tyrosine phosphatases that are involved in regulating the insulin receptor function [3], The discovery of vanadium-dependent haloperoxidases in marine algae and terrestrial lichens provided an additional stimulus in research toward obtaining functional models of peroxidase activity, and there is great interest in duplicating the function of these enzymes (see Section 10.4.2). 

Vilter, H. 1984. Peroxidases from Phaeophyceae A vanadium(V)-dependent peroxidase from Ascophylum nodosum. Phytochem. 23 1387-1390. 

H. Vilter, Peroxidases from Phaeophyceae a vanadium(V)-dependent peroxidase from A6C0phyZtum nodo6um, Phytochemistry 23 (1984) 1387-1390. 

VANADIUM ENZYMES/MODELS Vanadate-Dependent Peroxidases... 

SF2415B1 in a nonstereoselective fashion. This has opened up possible experimental approaches to understanding the absence of selectivity in other vanadium-dependent halo-peroxidases and identifying potentially stereoselective haloperoxidases from sequence data. 

Interestingly, a study of the bromide-dependent chloroperoxidase bromination of tyrosine reveals that the active brominating agent is free bromine and not a bromine-enzyme complex [122]. The situation is very different for bromoperoxidase- and vanadium peroxidase-catalyzed brominations [106-108]. 

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