Panasenko Oleg M, Spalteholz Holger, Schiller Jürgen, Arnhold Jürgen
Research Institute of Physico-Chemical Medicine, Moscow, Russia.
Free Radic Biol Med. 2003 Mar 1;34(5):553-62. doi: 10.1016/s0891-5849(02)01358-8.
The formation of lysophosphatidylcholines and chlorohydrins from unsaturated phosphatidylcholines upon the treatment with the myeloperoxidase-hydrogen peroxide-chloride system was evaluated by means of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Lyso-products were primarily found in phosphatidylcholine samples containing highly unsaturated fatty acid residues such as arachidonic or docosahexenoic acid. On the other hand, chlorohydrins dominate in mono- or bis-unsaturated phosphatidylcholines. No formation of these products was detected in the absence of one of the components of the MPO-H(2)O(2)-Cl(-) system or in the presence of MPO inhibitors (sodium azide) or scavengers of hypochlorous acid (taurine, methionine). Thus, hypochlorous acid formed by the MPO-H(2)O(2)-Cl(-) system is responsible for the observed modification in unsaturated phosphatidylcholines. In the presence of the complete MPO system, lyso-products and chlorohydrins were only formed at pH values lower than pH 6.0 with an optimum at pH 4.3. In contrast, the reagent hypochlorous acid caused the formation of these products even at neutral pH values, indicating a clear dependence of the yield of products on the presence of undissociated HOCl. We conclude that the formation of lysophospholipids and chlorohydrins from unsaturated phosphatidylcholines by myeloperoxidase can be relevant in vivo under acute inflammatory conditions.
通过基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱法评估了用髓过氧化物酶-过氧化氢-氯化物体系处理不饱和磷脂酰胆碱时溶血磷脂酰胆碱和氯醇的形成。溶血产物主要存在于含有高度不饱和脂肪酸残基（如花生四烯酸或二十二碳六烯酸）的磷脂酰胆碱样品中。另一方面，氯醇在单不饱和或双不饱和磷脂酰胆碱中占主导地位。在不存在MPO-H₂O₂-Cl⁻体系的任何一种成分时，或在存在MPO抑制剂（叠氮化钠）或次氯酸清除剂（牛磺酸、蛋氨酸）时，未检测到这些产物的形成。因此，MPO-H₂O₂-Cl⁻体系形成的次氯酸是不饱和磷脂酰胆碱中观察到的修饰的原因。在完整的MPO体系存在下，溶血产物和氯醇仅在pH值低于6.0时形成，最适pH值为4.3。相比之下，试剂次氯酸即使在中性pH值下也会导致这些产物的形成，表明产物产率明显依赖于未离解的HOCl的存在。我们得出结论，在急性炎症条件下，髓过氧化物酶从不饱和磷脂酰胆碱形成溶血磷脂和氯醇在体内可能具有相关性。
