LINEAR EQUATION THAT DESCRIBES STEADY-STATE KINETICS OF ENZYMES AND SUBCELLULAR PARTICLES INTERACTING WITH TIGHTLY BOUND INHIBITORS
LINEAR EQUATION THAT DESCRIBES STEADY-STATE KINETICS OF ENZYMES AND SUBCELLULAR PARTICLES INTERACTING WITH TIGHTLY BOUND INHIBITORS
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DOI：
10.1042/bj1270321
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发表时间：
1972-01-01
影响因子：
4.1
通讯作者：
HENDERSON, PJ
中科院分区：
文献类型：
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作者：
HENDERSON, PJ
当一种酶对一种抑制剂表现出高亲和力时，该机制的稳态分析因正常剂量-反应曲线或倒数曲线的非线性而变得复杂。这里示出的是，剂量-响应测量生成抑制剂浓度除以抑制程度的线性图，对速度无抑制剂除以速度有抑制剂;酶的浓度可以从这些图的外推截距导出，并且抑制机制从斜率随底物浓度的变化的重新绘制。限制的情况下，几乎所有的抑制剂分子被绑定或几乎所有的自由被描述，连同当一个显着比例的基板成为绑定的情况。这种类型的分析表明，氧化磷酸化的抑制剂，如他霉素和bongkrekic酸，是紧密结合到大鼠肝线粒体。
When an enzyme exhibits a high affinity for an inhibitor, the steady-state analysis of the mechanism is complicated by the non-linearity of normal dose–response plots or of reciprocal replots. It is shown here that dose–response measurements generate a linear plot of inhibitor concentration divided by degree of inhibition against velocity without inhibitor divided by velocity with inhibitor; the concentration of enzyme may be derived from the extrapolated intercept of such plots, and the mechanism of inhibition from replots of the variation of the slope with substrate concentration. The limiting cases where virtually all inhibitor molecules are bound or virtually all are free are described, together with the situation when a significant proportion of the substrate becomes bound. This type of analysis indicates that the inhibitors of oxidative phosphorylation, rutamycin and bongkrekic acid, are tightly bound to rat liver mitochondria.