Bromoperoxidase activity and vanadium level of the brown alga Ascophyllum nodosum

Seasonal changes in proteomic profiles of Japanese kelp: Saccharina japonica (Laminariales, Phaeophyceae)

“…In recent years, it has been reported that in the brown alga Ascophyllum nodosum (Linnaeus) Le Jolis, growing in the tidal zone in the suburbs of Roscoff, France, the vBPO activity shows a seasonal variation that is similar to that observed in the amount of vanadium in the algal body; further, it shows high levels of activity from winter to spring (Hartung et al 2008). It is assumed that the seasonal difference in vBPO expression observed in laminarialean alga and fucalean alga, which grow in similar latitudes, reflects the difference in the survival strategy on the basis of their life histories.…”

Halogenation and Vanadium Haloperoxidases

“…In macroalgae, vanadium is mainly incorporated in VHPOs, and has shown seasonrelated variations in concentration (Hartung et al, 2008). A seasonal or tissue variation has also been observed for the haloperoxidase activities of different brown algae, including Pelvetia canaliculata, L. digitata, and A. nodosum (Almeida, …”

“…pH Humanes , and Melo, 2000;De Boer et al, 1986;Gall, K€ upper, and Kloareg, 2004;Hartung et al, 2008;Krenn, Tromp, and Wevers, 1989), or red algae such as C. pilulifera (Itoh and Shinya, 1994;Itoh et al, 1996); this suggests some roles of VHPOs in the physiology and growth of seaweeds. In algae, the iodine/bromine-concentrating mechanisms are thought to involve an oxidation step through the action of VHPO (K€ upper et al, 1998), and in L. digitata the predominance of iodide species in the cell walls of peripheral cells suggests the involvement of a VHPO that is specific for the oxidation of iodine (Verhaeghe et al, 2008b).…”

Parameters for bromination of pyrroles in bromoperoxidase-catalyzed oxidations

“…26 The enzyme was stored in tris-(hydroxymethyl)-aminomethane [Tris, that is, 2-amino-2-(hydroxymethyl)-1,3-propanediol]-buffered stock solutions (pH 9.0) at 4 C. The enzymatic activity was determined with the triiodide assay. 27 In this test, iodide is oxidized into triiodide, which is monitored in time-dependent photometric assay.…”

“…Activity values determined with the MCD-assay, which are abbreviated as U 0 MCD , are smaller than the U 0 T -values, because iodide oxidation occurs faster than bromide oxidation. 26 Activities of V Br PO(AnI)-preparations in the MCD-assay ranged between 127AE4 and 171AE2 U 0 MCD mg À1 (pH 6.5, phosphate buffer). To conduct steady-state-kinetic analysis, rates of enzymatic bromide oxidation under saturation conditions were determined for hydrogen peroxide concentrations that gradually were increased from 0.02 mM to 1.00 mM, as bromide concentrations were fixed between 1.00 mM and 400 mM.…”