Kanofsky J R, Wright J, Miles-Richardson G E, Tauber A I
J Clin Invest. 1984 Oct;74(4):1489-95. doi: 10.1172/JCI111562.
The myeloperoxidase (MPO)-hydrogen peroxide (H2O2)-halide systems were found to produce chemiluminescence at 1,268 nm, a characteristic emission band for singlet oxygen (1O2). The emission was enhanced by a factor of 29 +/- 5 in deuterium oxide and was inhibited by the 1O2 quenchers, histidine and azide ion. Inactivation of MPO with heat or with cyanide ion prevented light production. The combined weight of all data strongly supported the production of 1O2 by these enzyme systems. The amount of 1O2 produced was sensitive to the conditions employed. Under optimal conditions at pH 5, the MPO-H2O2-bromide (Br-) system produced 0.42 +/- 0.03 mol 1O2/mol H2O2 consumed, close to the theoretical value of 0.5 that was predicted by the reaction stoichiometry. In contrast, the MPO-H2O2-chloride (Cl-) system was much less efficient. The maximum yield of 1O2 was 0.09 +/- 0.02 mol/mol H2O2 consumed and required pH 4 and 5 mM H2O2. At higher pH, the 1O2 production rapidly decreased. The yield at pH 7 was 0.0004 +/- 0.0002 mol/mol H2O2 consumed. Enzyme inactivation was a major factor limiting the yield of 1O2 with both Cl- and Br-. While the MPO-H2O2-halide systems can efficiently produce 1O2, the conditions required are not physiologic, which suggests that the chemiluminescence of the stimulated neutrophil does not derive from 1O2 generated by a MPO mechanism.
髓过氧化物酶（MPO）-过氧化氢（H₂O₂）-卤化物系统被发现可在1268纳米处产生化学发光，这是单线态氧（¹O₂）的特征发射带。在重水中，发射增强了29±5倍，并受到¹O₂猝灭剂组氨酸和叠氮离子的抑制。用热或氰离子使MPO失活可阻止发光。所有数据的综合权重有力地支持了这些酶系统产生¹O₂。产生的¹O₂量对所采用的条件敏感。在pH 5的最佳条件下，MPO-H₂O₂-溴化物（Br⁻）系统每消耗1摩尔H₂O₂产生0.42±0.03摩尔¹O₂，接近反应化学计量学预测的0.5的理论值。相比之下，MPO-H₂O₂-氯化物（Cl⁻）系统效率要低得多。¹O₂的最大产率为每消耗1摩尔H₂O₂产生0.09±0.02摩尔，且需要pH 4和5 mM H₂O₂。在较高pH下，¹O₂的产生迅速减少。在pH 7时的产率为每消耗1摩尔H₂O₂产生0.0004±0.0002摩尔。酶失活是限制Cl⁻和Br⁻产生¹O₂产率的主要因素。虽然MPO-H₂O₂-卤化物系统可有效产生¹O₂，但所需条件并非生理条件，这表明受刺激的中性粒细胞的化学发光并非源自MPO机制产生的¹O₂。
