Antinociceptive structure-activity studies with enkephalin-based opioid glycopeptides
Antinociceptive structure-activity studies with enkephalin-based opioid glycopeptides
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DOI：
10.1124/jpet.104.069393
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发表时间：
2004-10-01
影响因子：
3.5
通讯作者：
Bilsky, EJ
中科院分区：
文献类型：
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作者：
Elmagbari, NO;Egleton, RD;Bilsky, EJ
阿片肽作为治疗药物的发展一直受到药代动力学问题的限制，包括稳定性和血脑屏障（BBB）的渗透性。阿片肽的糖基化可以增加肽的血清稳定性和血脑屏障的渗透。为了进一步确定静脉给药后优化体内抗痛觉效价的要求，我们采用固相9-氟酰甲基氧基氨基甲酸酯法合成了一系列基于脑啡肽的糖肽。这些化合物在第六个和其后的氨基酸残基（丝氨酸或苏氨酸）和附着的碳水化合物部分上存在差异。体外结合和功能性平滑肌生物测定表明，与未糖基化的母肽相比，添加单糖或双糖对糖肽的阿片受体亲和力或激动剂活性没有显著影响。在55度甩尾试验中，所有的糖肽在雄性ICR小鼠脑室内注射后都产生了有效的抗伤害性作用。计算出丝氨酸/苏氨酸和单糖组合的A（50）值非常相似，范围在0.02 ~ 0.09 nmol之间。将选定的化合物静脉注射给小鼠，并测试其抗伤性，以间接评估血清稳定性和血脑屏障渗透。所有测试的化合物都产生完全的抗痛觉作用，计算出的A（50）值在2.2至46.4 μ mol/kg之间，其中双糖的效力相当于或超过吗啡的每千克微摩尔。三糖或双糖和三糖单糖的替代导致抗痛觉效力的降低。这些结果为糖基化提高小肽的中枢神经系统生物利用度提供了额外的支持，并补充了我们正在进行的稳定性和血脑屏障渗透研究。
Development of opioid peptides as therapeutic agents has historically been limited due to pharmacokinetic issues including stability and blood-brain barrier (BBB) permeability. Glycosylation of opioid peptides can increase peptide serum stability and BBB penetration. To further define the requirements for optimizing in vivo antinociceptive potency following intravenous administration, we synthesized a series of enkephalin-based glycopeptides using solid phase 9-fluorenylmethyloxy carbamate methods. The compounds differed in the sixth and subsequent amino acid residues (Ser or Thr) and in the attached carbohydrate moiety. In vitro binding and functional smooth muscle bioassays indicated that the addition of mono- or disaccharides did not significantly affect the opioid receptor affinity or agonist activity of the glycopeptides compared with their unglycosylated parent peptides. All of the glycopeptides tested produced potent antinociceptive effects in male ICR mice following intracerebroventricular injection in the 55degreesC tail-flick test. The calculated A(50) values for the Ser/Thr and monosaccharide combinations were all very similar with values ranging from 0.02 to 0.09 nmol. Selected compounds were administered to mice intravenously and tested for antinociception to indirectly assess serum stability and BBB penetration. All compounds tested produced full antinociceptive effects with calculated A(50) values ranging from 2.2 to 46.4 mumol/kg with the disaccharides having potencies that equaled or exceeded that of morphine on a micromoles per kilogram basis. Substitution of a trisaccharide or bis- and tris-monosaccharides resulted in a decrease in antinociceptive potency. These results provide additional support for the utility of glycosylation to increase central nervous system bioavailability of small peptides and compliment our ongoing stability and blood-brain barrier penetration studies.