MS QUANTIFICATION OF 3 CHLOROTYROSINE IN HUMAN TISSUES AT ATTOMOLE SENSITIVITY

蛋白质的氧化修饰与一种 从动脉粥样硬化到衰老的各种过程。 确定潜在的氧化途径已被证明是困难的， 然而，由于缺乏明显氧化的特异性标志物 小路。此前的体外研究表明， 3-氯酪氨酸是髓过氧化物酶催化的一种特殊产物 氧化损伤和氯化氨基酸因此可以作为 体内吞噬细胞介导的组织损伤的指标。在这里我们 描述一种高度敏感和具体的分析方法 组织中3-氯酪氨酸含量的定量测定。化验结果 将气相色谱与稳定同位素稀释质相结合 光谱分析，它可以检测到人体内3-氯酪氨酸的含量。 一意孤行。此外，该方法具有很高的重复性， 样本间和样本内的变异系数为3%。这个 3-氯酪氨酸的特异性、敏感性和重复性 测定应该使这种方法对探索作用有用 髓过氧化物酶在体内催化氧化反应中的作用。

Oxidative modification of proteins has been implicated in a variety of processes ranging from atherosclerosis to aging. Identifying the underlying oxidation pathways has proven difficult, however, due to the lack of specific markers for distinct oxidation pathways. Previous in vitro studies demonstrated that 3-chlorotyrosine is a specific product of myeloperoxidase-catalyzed oxidative damage and that the chlorinated amino acid may thus serve as an index of phagocyte-mediated tissue injury in vivo. Here we describe a highly sensitive and specific analytical method for the quantification of 3-chlorotyrosine content of tissues. The assay combines gas chromatography with stable isotope dilution mass spectrometry, and it detects attomole levels of 3-chlrotyrosine in a single determination. Furthermore, the method is highly reproducible, with inter- and intra-sample coefficients of variance of <3%. The specificity, sensitivity, and reproducibility of 3-chlorotyrosine determin ation should make this method useful for exploring the role of myeloperoxidase in catalyzing oxidative reactions in vivo.