The molecular size of multiple opiate receptors

Abstract
The functional size of different types of opiate receptors was determined in situ by the radiation inactivation technique. The Mr of opiate binding sites was estimated to be about 90,000 daltons; the data revealed no significant differences between the molecular sizes of either μ-, δ- or ϰ-sites in rat brain membranes. An identical molecular size was found also for the δ-sites in the neuroblastoma x glioma hybrid cell clone, NG 108-15.