Oceanlab, University of Aberdeen, Main Street, Newburgh, AB41 6AA, Scotland, UK.
Dunstaffnage Marine Laboratory, Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, Scotland, UK.
J Biol Inorg Chem. 2018 Oct;23(7):1119-1128. doi: 10.1007/s00775-018-1539-7. Epub 2018 Mar 9.
This study explores key features of bromine and iodine metabolism in the filamentous brown alga and genomics model Ectocarpus siliculosus. Both elements are accumulated in Ectocarpus, albeit at much lower concentration factors (2-3 orders of magnitude for iodine, and < 1 order of magnitude for bromine) than e.g. in the kelp Laminaria digitata. Iodide competitively reduces the accumulation of bromide. Both iodide and bromide are accumulated in the cell wall (apoplast) of Ectocarpus, with minor amounts of bromine also detectable in the cytosol. Ectocarpus emits a range of volatile halogenated compounds, the most prominent of which by far is methyl iodide. Interestingly, biosynthesis of this compound cannot be accounted for by vanadium haloperoxidase since the latter have not been found to catalyze direct halogenation of an unactivated methyl group or hydrocarbon so a methyl halide transferase-type production mechanism is proposed.
本研究探讨了丝状褐藻和基因组模型泡叶藻中溴和碘代谢的关键特征。这两种元素都在泡叶藻中积累，尽管浓度因子要低得多（碘为 2-3 个数量级，溴小于 1 个数量级），例如在巨藻中。碘化物竞争性地减少溴化物的积累。碘化物和溴化物都积累在泡叶藻的细胞壁（质外体）中，胞质溶胶中也检测到少量的溴。泡叶藻会释放一系列挥发性卤代化合物，其中最突出的是迄今为止的甲基碘。有趣的是，由于尚未发现钒卤过氧化物酶直接卤化未活化的甲基或碳氢化合物，因此无法用其来解释该化合物的生物合成，因此提出了一种甲基卤化物转移酶型生产机制。
