Copeland E S, deBaare L
Biophys J. 1976 Nov;16(11):1245-55. doi: 10.1016/S0006-3495(76)85771-2.
Morphine, spin labeled on the 3- or 6-position has been used as the opiate ligand in a study of the time course of stereospecific opiate binding to intact synaptosomes isolated from non-cerebellar rat brain. The broadening of electron spin resonance lines induced by immobilization of the ligand on binding has been used to determine the concentration of bound opiate. The stereospecificity of the reaction was measured by comparing ligand binding in the presence of thousand-fold molar excesses of dextrorphan or levorphanol. Using both static and flow techniques, the binding process has been continuously monitored at times greater than 4.8 s after mixing spin labeled morphine with synaptosomes. It is shown that for this ligand and receptor preparation, binding takes place primarily during a delayed, abrupt process whose rate and time of onset are temperature dependent and reflect the presence of added opiate agonist or antagonist.
在一项关于立体特异性阿片类药物与从非小脑大鼠脑部分离的完整突触体结合的时间进程研究中，3位或6位自旋标记的吗啡被用作阿片类配体。配体在结合时固定化所诱导的电子自旋共振线变宽已被用于确定结合的阿片类药物浓度。通过比较在千倍摩尔过量右啡烷或左啡诺存在下的配体结合来测量反应的立体特异性。使用静态和流动技术，在将自旋标记的吗啡与突触体混合后大于4.8秒的时间内持续监测结合过程。结果表明，对于这种配体和受体制剂，结合主要发生在一个延迟的、突然的过程中，其速率和起始时间取决于温度，并反映了添加的阿片类激动剂或拮抗剂的存在。
