Kiryu C, Makiuchi M, Miyazaki J, Fujinaga T, Kakinuma K
Biophotonics Information Laboratories, Yamagata Advanced Technology Research Center, Japan.
FEBS Lett. 1999 Jan 25;443(2):154-8. doi: 10.1016/s0014-5793(98)01700-1.
The putative role of singlet oxygen (1O2) in the respiratory burst of neutrophils has remained elusive due to the lack of reliable means to study its quantitative production. To measure 1O2 directly from biological or chemical reactions in the near infrared region, we have developed a highly sensitive detection system which employs two InGaAs/InP pin photodiodes incorporated with a dual charge integrating amplifier circuit. Using this detection system, we detected light emission derived from a myeloperoxidase (MPO)-mediated reaction in physiological conditions: pH 7.4, 1-30 nM MPO, 10-100 microM H2O2 and 100-130 mM CI in place of Br without the use of deuterium oxide. The MNPO-H2O2-CI(-) system exhibited a single emission peak at 1.27 microm with a spectral distribution identical to that of delta singlet oxygen. Our results suggest physiological production of 1O2 in the MPO-H2O2-CI(-) system at an intravacuolar neutral pH. The MPO-mediated generation of 1O2, which may have an important role in host defense mechanisms, is discussed in connection with previous results.
由于缺乏研究单线态氧（¹O₂）定量生成的可靠方法，其在中性粒细胞呼吸爆发中的假定作用一直难以捉摸。为了在近红外区域直接测量生物或化学反应中的¹O₂，我们开发了一种高度灵敏的检测系统，该系统采用了两个与双电荷积分放大电路相结合的铟镓砷/磷化铟pin光电二极管。使用该检测系统，我们在生理条件下（pH 7.4、1 - 30 nM髓过氧化物酶（MPO）、10 - 100 μM过氧化氢和100 - 130 mM氯离子代替溴且不使用重水）检测到了髓过氧化物酶介导反应产生的光发射。MPO - H₂O₂ - Cl⁻系统在1.27微米处呈现出一个单一发射峰，其光谱分布与δ单线态氧相同。我们的结果表明，在液泡内中性pH条件下，MPO - H₂O₂ - Cl⁻系统中可生理性产生¹O₂。结合先前的结果，讨论了MPO介导的¹O₂生成在宿主防御机制中可能具有的重要作用。
