Esterification of okadaic acid in the mussel Mytilus galloprovincialis
Esterification of okadaic acid in the mussel Mytilus galloprovincialis
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DOI：
10.1016/j.toxicon.2011.02.003
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发表时间：
2011-04-01
期刊：
影响因子：
2.8
通讯作者：
Blanco, Juan
中科院分区：
文献类型：
--
作者：
Rossignoli, Araceli E.;Fernandez, David;Blanco, Juan
冈田酸和其他腹泻性贝类毒素在双壳类中主要转化为其酰基衍生物。最近的一些研究表明，双壳类肠道中的细菌可能对毒素的酰化作用有很大贡献。通过给贻贝喂食含有冈田酸的微胶囊，我们明确地表明，摄入的冈田酸几乎完全转化为其脂肪酸酯(酰基衍生物)。用抗生素处理贻贝对供应的冈田酸的酰化没有任何显著影响，这表明细菌在这一过程中不起任何重要作用。消化腺细胞的微粒体和线粒体亚细胞部分已被证明含有能够将脂肪酸分子从辅酶A转移到冈田酸的酶(因此，具有酰辅酶A：OA酰基转移酶活性)。这种活性与内质网的标志物细胞色素C还原酶(NADPH)的活性有关，表明该细胞器是酰化过程的主要负责者。DSP毒素的酰化似乎是从贻贝中分离这些毒素的关键步骤，因为这些化合物以酰基衍生物的形式存在于粪便中。对于大多数双壳类来说，这可能是真的。酰基衍生物的累积比例可以指向纯化的关键过程：酰化或酰化衍生物的排泄。在贻贝、紫贻贝和杜氏贻贝中，第一个过程似乎是最重要的，但在大多数双壳类物种中，它似乎是第二个过程。此外，还讨论了纯化和酰化反应之间关系的其他方面。(C)2011爱思唯尔有限公司。保留所有权利。
Okadaic acid and other toxins of the diarrheic shellfish poisoning (DSP) group are transformed mainly to their acyl-derivatives in bivalves. Some recent studies suggest that bacteria present in the bivalve gut could contribute substantially to the acylation of the toxins. By feeding microcapsules containing okadaic acid to mussels we have shown unequivocally that the ingested okadaic acid is nearly completely transformed to its fatty acid esters (acyl-derivatives). Treating mussels with antibiotics did not have any significant effect on the acylation of the supplied okadaic acid, suggesting that bacteria do not play any significant role in this process. The microsomal and mitochondrial subcellular fractions of the cells of the digestive gland have been shown to have contain enzymes that are able to transfer a fatty acid molecule from Coenzyme A to okadaic acid (so, that have Acyl-CoA:OA acyltransferase activity). This activity was related to that of the enzyme Cytochrome C reductase (NADPH), a marker of endoplasmic reticulum, suggesting that this organelle is the main responsible for the acylation process. Acylation of DSP toxins seems to be a key step in the deputation of these toxins from mussels, as these compounds are found in feces as acyl-derivatives. This is probably true for most bivalves. The proportion of acyl-derivatives accumulated can point to the key process of the depuration: acylation or excretion of acylated derivatives. In the mussels Mytilus galloprovincialis, Mytilus edulis and in Donax trunculus, the first process seems to be the most important, but in most bivalve species it seems to be the second one. Other aspects of the relationship between depuration and acylation are also discussed. (C) 2011 Elsevier Ltd. All rights reserved.