Svensson B E, Gräslund A, Ström G, Moldeus P
Department of Neuropharmacology, Astra Arcus AB, Södertälje, Sweden.
Free Radic Biol Med. 1993 Feb;14(2):167-75. doi: 10.1016/0891-5849(93)90007-h.
The abilities of haem peroxidases to catalyse the oxidation of various thiols were studied using the spin-trapping electron spin resonance (ESR) technique. Myeloperoxidase, a neutrophil and monocyte enzyme, catalysed the oxidation of cysteamine, cysteine methyl, and ethyl ester and to some extent 2-mercaptoethanol and thioglycollic acid. This peroxidase poorly catalysed the oxidation of cysteine, N-acetylcysteine, penicillamine, and glutathione under the same conditions. The dependence on pH of peroxidase-catalysed thiol oxidation may indicate that the thiolate anion form is the actual peroxidase substrate. Another leucocyte peroxidase, eosinophil peroxidase, had similar catalytic properties toward thiols as myeloperoxidase. Lactoperoxidase (found in milk, saliva, and tears) and the plant horseradish peroxidase were, however, different from the aforementioned leucocyte peroxidases in their abilities to catalyse the oxidation of thiols.
利用自旋捕获电子自旋共振（ESR）技术研究了血红素过氧化物酶催化各种硫醇氧化的能力。髓过氧化物酶是一种存在于中性粒细胞和单核细胞中的酶，它能催化半胱胺、半胱氨酸甲酯和乙酯的氧化，在一定程度上还能催化2-巯基乙醇和巯基乙酸的氧化。在相同条件下，这种过氧化物酶对催化半胱氨酸、N-乙酰半胱氨酸、青霉胺和谷胱甘肽的氧化作用较弱。过氧化物酶催化硫醇氧化对pH的依赖性可能表明硫醇盐阴离子形式是实际的过氧化物酶底物。另一种白细胞过氧化物酶，即嗜酸性粒细胞过氧化物酶，对硫醇的催化特性与髓过氧化物酶相似。然而，乳过氧化物酶（存在于牛奶、唾液和眼泪中）和植物辣根过氧化物酶在催化硫醇氧化的能力方面与上述白细胞过氧化物酶不同。
