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Cytochrome oxidase and proton translocation

细胞色素氧化酶和质子易位

基本信息

批准号：
02454559
负责人：
ORII Yutaka
金额：
$ 4.42万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

1. In order to collect fundamental data for establishing the system to measure the concentration of tissue oxygen by utilizing a laser flash photolysis technique, a rapid-scan spectrophotometer, double-flash spectrophotometer and a time-resolved absorption spectrophotometer were constructed. Both rapid-scan and double-flash apparatuses are of the highest performance ever built in the world; the former allows to record 512 consecutive absorption and reflectance spectra of a 200-nm span at the maximum time resolution of 1 ms, and the latter has a time resolution of 1mus. These apparatuses have been used extensively in wide areas of related fields. One of remarkable achievements is the finding of the functional role of yeast flavohemoglobin as an oxygen sensor.2. Oxygenation process of myoglobin contained in meat was followed spectrally by using the rapid-scan apparatus in combination with an optical probe made of optical fibers. Upon exposure of the interior to air oxygen by dissecting a meat lump, a color of the cut surface changes from dark brown to bright red. The spectral changes clearly indicate the formation of oxymyoglobin which is characterized by a growth of peaks at 582 and 540 nm with an isosbestic point at 591 nm. The absorbance changes followed at 582 nm against 591 nm as reference are invariably biphasic.3. The photodissociation of oxyhemoglobin and its recombination process have been studied by utilizing all of the apparatuses constructed and relevant kinetic data were collected at varying oxygen concentrations. These kinetic parameters are correlated with the oxygen concentration and the procedure to measure the oxygen concentration in solution has been established. Based on these data a variety of problems involved in the determination of tissue oxygen concentrations are revealed.

1.为建立利用激光闪光光解技术测量组织氧浓度的系统提供基础数据，建立了快速扫描分光光度计、双闪分光分光光度计和时间分辨吸收分光光度计。快扫描和双闪装置都是世界上建造的性能最高的装置；前者允许在最大时间分辨率为1ms的情况下记录200 nm跨度的512个连续的吸收和反射光谱，后者的时间分辨率为1微秒。这些仪器在相关领域得到了广泛的应用。其中一个显著的成就是发现了酵母黄色素作为氧气感受器的功能作用。利用快速扫描仪与光纤光学探头相结合，对肉类中肌红蛋白的氧化过程进行了光谱分析。通过解剖肉块将内部暴露在氧气中后，切割表面的颜色从深棕色变为鲜红色。光谱的变化清楚地表明了氧合肌球蛋白的形成，其特征是在582和540 nm处有峰的生长，在591 nm处有一个等色点。以591 nm为参照物，在582 nm处的吸光度变化始终是双相的。利用所建立的装置研究了氧合血红蛋白的光解离及其复合过程，并在不同氧浓度下收集了相关的动力学数据。将这些动力学参数与氧浓度进行了关联，建立了测定溶液中氧浓度的方法。基于这些数据，揭示了组织氧浓度测定中涉及的各种问题。