Abood L G, Salem N, MacNeil M, Butler M
Biochim Biophys Acta. 1978 Jul 25;530(1):35-46. doi: 10.1016/0005-2760(78)90124-8.
A study has been made of the role of phosphatidylserine in stereospecific opiate binding to neural membranes, utilizing specific lipolytic enzymes to attack the lipid. At very low concentrations phospholipase A2 from bee venom will preferentially hydrolyze C22:6-fatty acid; and even after a few percent of the total phosphatidylserine is hydrolyzed, opiate binding is greatly inhibited. The addition of brain phosphatidylserine will restore opiate binding; however, when the inhibition approaches 50% restoration is only partial. Exposure of membranes to phosphatidylserine decarboxylase will partially inhibit opiate binding; and the binding returns to the control level after the addition of phosphatidylserine. The partial inhibition of opiate binding by low concentrations of Triton X-100, which presumably remove lipids, can be partially reversed by phosphatidylserine. The binding of 3H-naloxone, an opiate antagonist, is similar to agonists in its behavior towards phospholipases and phosphatidylserine; however, binding of naltrexone, also an antagonist, is far less responsive. It is concluded that the phosphatidylserine associated with the opiate receptor is the C18:0, 22:6-diacyl form, which is closely associated with protein.
利用特定的脂解酶攻击脂质，对磷脂酰丝氨酸在立体特异性阿片类药物与神经膜结合中的作用进行了研究。在极低浓度下，来自蜂毒的磷脂酶A2会优先水解C22:6脂肪酸；即使在总磷脂酰丝氨酸的百分之几被水解后，阿片类药物的结合也会受到极大抑制。添加脑磷脂酰丝氨酸可恢复阿片类药物的结合；然而，当抑制接近50%时，恢复只是部分的。将膜暴露于磷脂酰丝氨酸脱羧酶会部分抑制阿片类药物的结合；添加磷脂酰丝氨酸后，结合恢复到对照水平。低浓度的 Triton X-100（可能会去除脂质）对阿片类药物结合的部分抑制可被磷脂酰丝氨酸部分逆转。阿片类拮抗剂3H-纳洛酮的结合在对磷脂酶和磷脂酰丝氨酸的反应方面与激动剂相似；然而，同样是拮抗剂的纳曲酮的结合反应则小得多。得出的结论是，与阿片受体相关的磷脂酰丝氨酸是C18:0、22:6-二酰基形式，它与蛋白质紧密相关。
