DEVELOPMENT OF RECEPTOR-SPECIFIC OPIOID PEPTIDE ANALOGS

描述（由申请人提供）：临床上迫切需要开发具有新生物活性特征的阿片类镇痛药，其缺乏阿片类镇痛药的限制性副作用。 现有的鸦片制剂。该项目涉及开发阿片类激动剂和具有混合活性特征的化合物，作为药理学工具和预期产生较少副作用的镇痛剂。在具体目标1中，将合成含有取代酪氨酸-1的新型苯丙氨酸类似物的阿片肽激动剂。这些化合物被设计成具有不同的阿片受体结合模式，并诱导或识别不同的受体构象。因此，这些化合物在受体信号传导或内化方面可以表现为功能选择性或偏向性激动剂，并且具有作为镇痛剂的潜力，副作用减少（例如耐受性发展）。其中一些肽将以糖基化形式制备，以改善血脑屏障（BBB）的渗透性。化合物将在阿片受体结合测定和功能测定、受体磷酸化和内化研究、电生理学研究（Ca 2+通道活性）和生物发光共振能量转移（BRET）实验中进行表征，以鉴定受体与各种信号传导效应物和抑制蛋白的相互作用。将使用两种炎性疼痛模型来确定抗伤害感受效力和镇痛耐受性发展。具体目标2是基于以下观察结果：联合给药的<$阿片类激动剂和<$阿片类激动剂协同作用，产生强效抗伤害作用，从而为开发混合<$激动剂/<$激动剂作为产生较少副作用的中枢作用镇痛剂提供了理论基础。提出制备新的双功能化合物，其结合了与阿片肽[Dmt 1]DALDA连接的各种阿片激动剂，所述阿片肽具有作为激动剂组分和作为BBB穿透载体的双重作用。将在体外表征化合物，并在急性疼痛模型中测定其抗伤害感受效力。将检查他们产生镇痛耐受性、身体依赖性、便秘和呼吸抑制的倾向。具体目标3涉及混合的激动剂/拮抗剂的持续开发，其被证明具有作为中枢作用镇痛剂的潜力，具有产生激动剂如吗啡的典型副作用的低倾向。这种双功能化合物的一种设计再次使用[Dmt 1]DALDA作为激动剂组分和BBB穿透载体，各种中性拮抗剂、反向激动剂或部分激动剂将连接到所述载体。在另一种设计中，糖基化类似物的激动剂/拮抗剂DIPP-NH 2 [？]将做好准备，努力提高其穿越BBB的能力。体外和体内药理学表征将如目的2所述。

DESCRIPTION (provided by applicant): There is an urgent clinical need for the development of opioid analgesics with novel biological activity profiles that lack the limiting side effects of currently available opiates. This project concerns the development of ¿ opioid agonists and of compounds with mixed ¿/¿ activity profiles as pharmacological tools and as analgesics expected to produce fewer side effects. In Specific Aim 1, ¿ opioid peptide agonists containing novel phenylalanine analogues in place of tyrosine-1 will be synthesized. These compounds have been designed to have distinct ¿ opioid receptor binding modes and to induce or recognize a distinct receptor conformation. Therefore, these compounds may behave as functionally selective or biased ¿ agonists with regard to receptor signaling or internalization and have potential as analgesics with reduced side effects (e.g. tolerance development). Some of these peptides will be prepared in glycosylated form to improve blood-brain barrier (BBB) permeability. The compounds will be pharmacologically characterized in opioid receptor binding assays and functional assays, ¿ receptor phosphorylation and internalization studies, electrophysiological studies (Ca2+ channel activity) and bioluminescence resonance energy transfer (BRET) experiments for the identification of ¿ receptor interactions with various signaling effectors and ¿-arrestin. Two inflammatory pain models will be used to determine antinociceptive potencies and analgesic tolerance development. Specific Aim 2 is based on the observation that co-administered ¿ and ¿ opioid agonists act synergistically to produce a potent antinociceptive effect, thus providing the rationale for the development of mixed ¿ agonist/¿ agonists as centrally acting analgesics producing fewer side effects. It is proposed to prepare novel bifunctional compounds incorporating various ¿ opioid agonists linked to the opioid peptide [Dmt1]DALDA which has a dual role as ¿ agonist component and as BBB-penetrating vector. Compounds will be characterized in vitro and their antinociceptive potencies will be determined in acute pain models. Their propensities to produce analgesic tolerance, physical dependence, constipation and respiratory depression will be examined. Specific Aim 3 concerns the continued development of mixed ¿ agonist/¿ antagonists with demonstrated potential as centrally acting analgesics having low propensity to produce the typical side effects of ¿ agonists like morphine. One design of such bifunctional compounds makes again use of [Dmt1]DALDA as ¿ agonist component and BBB-penetrating vector to which various ¿ neutral antagonists, inverse agonists or partial agonists will be linked. In another design glycosylated analogues of the ¿ agonist/¿ antagonist DIPP-NH2[?] will be prepared in an effort to improve its ability to cross the BBB. The in vitro and in vivo pharmacological characterization will be as in Aim 2.