Newman E L, Barnard E A
Biochemistry. 1984 Nov 6;23(23):5385-9. doi: 10.1021/bi00318a001.
The enkephalin affinity reagent [3H]Tyr-D-Ala-Gly-Phe-Leu-CH2Cl [( 3H]DALECK) was synthesized. It exhibited high-affinity reversible binding, at pH 7.4, to both mu and delta opioid receptor sites in rat brain membranes. At pH 8.1, nanomolar levels of [3H]DALECK produced an irreversible labeling in synaptic membranes, essentially only in one subunit of 58 000 daltons. The irreversible phase of the reaction reduced the subsequent binding of a mu-selective enkephalin derivative but not that of a delta-selective one. It is concluded that a mu subunit of the opioid receptor exists, can be alkylated specifically, and is of Mr 58 000.
脑啡肽亲和试剂[3H]酪氨酰-D-丙氨酰-甘氨酰-苯丙氨酰-亮氨酰-氯甲烷([3H]DALECK)已合成。在pH 7.4时，它对大鼠脑膜中的μ和δ阿片受体位点均表现出高亲和力的可逆结合。在pH 8.1时，纳摩尔浓度的[3H]DALECK在突触膜中产生不可逆标记，基本上仅在一个58000道尔顿的亚基中。反应的不可逆阶段降低了随后μ选择性脑啡肽衍生物的结合，但不影响δ选择性脑啡肽衍生物的结合。结论是阿片受体的μ亚基存在，可被特异性烷基化，其分子量为58000。
