Protein adduct-trapping by hydrazinophthalazine drugs: Mechanisms of cytoprotection against acrolein-mediated toxicity
Protein adduct-trapping by hydrazinophthalazine drugs: Mechanisms of cytoprotection against acrolein-mediated toxicity
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DOI：
10.1124/mol.65.3.655
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发表时间：
2004-03-01
影响因子：
3.6
通讯作者：
Pyke, SM
中科院分区：
文献类型：
--
作者：
Burcham, PC;Fontaine, FR;Pyke, SM
丙烯醛是一种高毒性的醛，与许多疾病以及药物诱导的毒性有关。其明显的毒性反映了它在蛋白质和DNA中形成加合物的容易性。作为双功能亲电体，丙烯醛和蛋白质之间的初始反应产生含有亲电中心的加合物，该加合物可以参与次级有害反应（例如，交联）。我们推测，这些反应蛋白加合物与亲核药物的失活可能会抵消丙烯醛毒性。因为我们以前观察到，1-肼基酞嗪（肼苯哒嗪）强烈降低丙烯醛前体烯丙醇的毒性，我们探讨了肼苯哒嗪靶向蛋白质中反应性丙烯醛加合物的可能性。我们报告说，肼苯哒嗪废除了丙烯醛修饰的模型蛋白（牛血清白蛋白）的免疫反应性，但只有当药物被添加到蛋白质开始修改由丙烯醛在30分钟内。一系列羰基捕获药物干扰蛋白质修饰的“早期”事件的能力与其对肝细胞中烯丙醇毒性的保护效力密切相关。在使用含赖氨酸的肽模型的质谱研究中，肼苯哒嗪与丙烯醛产生的迈克尔加合物迅速形成腙。在Western印迹实验中，使用针对这种三元药物-丙烯醛-蛋白质复合物的抗体，在暴露于2至50 μ M的肼苯哒嗪的细胞保护浓度的丙烯醛预载肝细胞中，清楚的加合物捕获是明显的。这些新的发现开始揭示肼苯哒嗪作为一种有效的“蛋白加合物捕获”药物的分子机制。
Acrolein is a highly toxic aldehyde involved in a number of diseases as well as drug-induced toxicities. Its pronounced toxicity reflects the readiness with which it forms adducts in proteins and DNA. As a bifunctional electrophile, initial reactions between acrolein and protein generate adducts containing an electrophilic center that can participate in secondary deleterious reactions (e.g., cross-linking). We hypothesize that inactivation of these reactive protein adducts with nucleophilic drugs may counteract acrolein toxicity. Because we previously observed that 1-hydrazinophthalazine (hydralazine) strongly diminishes the toxicity of the acrolein precursor allyl alcohol, we explored the possibility that hydralazine targets reactive acrolein adducts in proteins. We report that hydralazine abolished the immunoreactivity of an acrolein-modified model protein (bovine serum albumin), but only if the drug was added to the protein within 30 min of commencing modification by acrolein. The ability of a range of carbonyl-trapping drugs to interfere with "early" events in protein modification strongly correlated with their protective potencies against allyl alcohol toxicity in hepatocytes. In mass spectrometry studies using a model lysine-containing peptide, hydralazine rapidly formed hydrazones with Michael adducts generated by acrolein. Using an antibody raised against such ternary drug-acrolein-protein complexes in Western blotting experiments, clear adduct-trapping was evident in acrolein-preloaded hepatocytes exposed to cytoprotective concentrations of hydralazine ranging from 2 to 50 muM. These novel findings begin to reveal the molecular mechanisms whereby hydralazine functions as an efficient "protein adduct-trapping" drug.