Department of Chemistry and Materials Science, Faculty of Experimental Sciences, University of Huelva, Campus de El Carmenm, Fuerzas Armadas Ave., 21007 Huelva, Spain.
Biometals. 2013 Aug;26(4):639-50. doi: 10.1007/s10534-013-9636-0. Epub 2013 Jun 21.
Characterization of Cd-binding proteins has great analytical interest due to the high toxicity of Cd to living organisms. Metallothioneins (MTs), as Cd(II)-binding proteins are of increasing interest, since they form very stable Cd chelates and are involved in many detoxification processes. In this work, inductively coupled plasma octopole reaction cell mass spectrometry and nanospray ionization time-of-flight mass spectrometry were used in parallel and combined with two-dimensional chromatography: size exclusion followed by reversed-phase high performance liquid chromatography, to study metal complexes of MT isoforms produced in hepatic cytosols of Mus musculus during exposure experiments to Cd. Exposure experiments were carried out by subcutaneous injection of a growing dose of the toxic element ranging from 0.1 to 1.0 mg of Cd per kg of body weight per day during 10 days. A control group and three exposure groups at days 2, 6 and 10 of exposure were studied, and different cadmium, copper and zinc complexes with MTs isoforms were isolated and characterized from the two most exposed groups. The results allow gaining insight into the mechanisms involved in metal detoxification by MTs, showing the changes in the stoichiometry of metal complexes-MTs along cadmium exposure.
由于 Cd 对生物体具有很高的毒性，因此对 Cd 结合蛋白进行特性描述具有重要的分析意义。金属硫蛋白（MTs）作为 Cd(II)结合蛋白，由于其能形成非常稳定的 Cd 螯合物并参与许多解毒过程，因此受到越来越多的关注。在这项工作中，我们平行使用电感耦合等离子体八极反应池质谱和纳喷雾电离飞行时间质谱，并结合二维色谱法：体积排阻 followed by 反相高效液相色谱法，来研究 Cd 暴露实验中 Mus musculus 肝胞质中产生的 MT 同工型的金属络合物。通过皮下注射进行暴露实验，每天每公斤体重注射 0.1 到 1.0 毫克的有毒元素，持续 10 天。研究了对照组和暴露 2、6 和 10 天的三组暴露组，从两个暴露最严重的组中分离和鉴定出不同的 Cd、Cu 和 Zn 与 MTs 同工型的络合物。结果使我们深入了解 MTs 参与金属解毒的机制，显示了随着 Cd 暴露，金属络合物-MTs 的化学计量比发生变化。
