Differential effects of protein-modifying reagents on receptor binding of opiate agonists and antagonists.
Differential effects of protein-modifying reagents on receptor binding of opiate agonists and antagonists.
复制标题
蛋白质修饰试剂对阿片激动剂和拮抗剂受体结合的不同影响。
作者：
G. Pasternak;H. A. Wilson;S. Snyder
阿片受体结合通过事先的孵育而增强，从而去除受体结合的内源性抑制剂。影响巯基的蛋白质修饰试剂不同程度地影响激动剂和拮抗剂与阿片受体的结合。这些试剂，包括碘乙酰胺、n -乙基马来酰亚胺、醋酸汞、汞酰酸、对氨基苯基醋酸汞和对氯汞苯甲酸，在不影响[3H]纳洛酮结合的浓度下，强烈抑制[3H]二氢吗啡的结合。先前用阿片类药物治疗可以保护受体不受试剂的影响。这些试剂减少了二氢吗啡结合位点的表观数量，但不改变它们的亲和力，同时也增加了激动剂结合对钠抑制作用的敏感性。
Opiate receptor binding is enhanced by prior incubation, which removes an endogenous inhibitor of receptor binding. Protein-modifying reagents which affect sulfhydryl groups differentially influence the binding of agonists and antagonists to the opiate receptor. These reagents, including iodoacetamide, N-ethylmaleimide, mercuriacetate, mersalyl acid, p-aminophenylmercuric acetate, and p-chloromercuribenzoate, strongly inhibit [3H]dihydromorphine binding at concentrations which do not affect [3H]naloxone binding. Prior treatment with opiates protects the receptor binding from reagents. The reagents decrease the apparent number of dihydromorphine binding sites without altering their affinity, and also increase the sensitivity of agonist binding to the inhibitory effects of sodium.