Tsan M F
J Cell Physiol. 1982 Apr;111(1):49-54. doi: 10.1002/jcp.1041110109.
The myeloperoxidase-mediated oxidation of methionine was studied using a purified canine myeloperoxidase preparation. The system required the simultaneous presence of myeloperoxidase, H2O2, and a halide anion. When 0.1 mM H2O2 was used, the system has a Ph optimum of approximately pH 5-5.5. Bromide and iodide were much more effective than chloride in the myeloperoxidase-mediated oxidation of methionine. Horseradish peroxidase was unable to oxidize methionine whether chloride or iodide was used. In contrast, lactoperoxidase oxidized methionine in the presence of iodide but not chloride. Based on studies of 1) the effect of various inhibitors and singlet oxygen quenchers, as well as 2) the effect of D2O on the oxidation of methionine, by the myeloperoxidase system, OCI-, or methylene blue, it was shown that the oxidation of methionine by the myeloperoxidase system was not mediated by OCI- or 1O2. The mechanism of the myeloperoxidase-mediated oxidation of methionine remains unclear. However, it may be one mechanism by which the myeloperoxidase system damage microorganisms.
使用纯化的犬髓过氧化物酶制剂研究了髓过氧化物酶介导的甲硫氨酸氧化。该系统需要同时存在髓过氧化物酶、H2O2和卤化物阴离子。当使用0.1 mM H2O2时，该系统的最适pH约为5 - 5.5。在髓过氧化物酶介导的甲硫氨酸氧化中，溴化物和碘化物比氯化物更有效。无论使用氯化物还是碘化物，辣根过氧化物酶都无法氧化甲硫氨酸。相比之下，乳过氧化物酶在碘化物存在下可氧化甲硫氨酸，但在氯化物存在下则不能。基于对1）各种抑制剂和单线态氧猝灭剂的作用，以及2）D2O对髓过氧化物酶系统、OCI-或亚甲蓝介导的甲硫氨酸氧化的影响的研究，结果表明髓过氧化物酶系统对甲硫氨酸的氧化不是由OCI-或1O2介导的。髓过氧化物酶介导的甲硫氨酸氧化机制尚不清楚。然而，它可能是髓过氧化物酶系统损伤微生物的一种机制。
