DEVELOPMENT OF RECEPTOR-SPECIFIC OPIOID PEPTIDE ANALOGS

描述（由申请人提供）：我们提出合成有效的、稳定的和生物可利用的阿片肽类似物，其被设计为i）对μ-、δ-或κ-阿片受体及其亚型具有高选择性的拮抗剂或反向激动剂作为药理学工具，和ii）具有混合激动剂/拮抗剂特征的阿片化合物用于可能的治疗应用。为了实现这些目标，我们使用跨学科的方法，结合有机合成，肽化学，广泛的药理学表征和构象研究。具体目标1是基于我们最近的发现，即3-（2，6-二甲基-4-羟基苯基）丙酸（Dhp）取代阿片肽中的N-末端酪氨酸残基产生μ-、δ-或κ-受体的拮抗剂。我们将合成Dhp类似物，用于取代阿片肽中的Tyr 1，这些肽能够与受体部分进行各种潜在的疏水或氢键相互作用，期望获得更有效的拮抗剂或反向激动剂，或具有混合K激动剂/U拮抗剂特征的化合物。在具体目标2中，我们将用具体目标1中开发的Dhp类似物替代已知选择性κ-、δ-或μ-激动剂阿片肽中的Tyr 1，以将它们转化为对κ-、δ-或μ-受体及其亚型具有选择性的拮抗剂或反向激动剂。在具体目标3中，我们将通过最近从真菌Ctenomyces serratus分离的环状四肽c[Phe-D-Pro-Phe-（D，L）-Trp]（CJ-15，208）的结构修饰来开发有效的K阿片拮抗剂或反向激动剂。在具体目标4中，我们将确定含有特定目标1下开发的某些Dhp类似物的阿片肽类似物，其具有混合的K激动剂/mu拮抗剂特征，作为治疗可卡因滥用的潜在药物。具体目标5涉及开发具有混合μ激动剂/δ拮抗剂特征的嵌合阿片肽作为镇痛剂，其具有产生耐受性和依赖性的低倾向。将通过进行阿片受体结合试验、豚鼠回肠和小鼠输精管试验以及[35 S] GTP γ S结合试验来确定体外阿片活性特征。一些化合物的体内表征将包括确定对可卡因辨别和K激动剂/μ拮抗剂自我给药的影响，以及混合μ激动剂/δ拮抗剂的镇痛试验，包括耐受性和依赖性的形成。将通过1HNMR光谱结合理论构象分析检查选定化合物的构象。

DESCRIPTION (provided by applicant): We propose to synthesize potent, stable and bioavailable opioid peptide analogues designed to be i) antagonists or inverse agonists with high selectivity for mu-, delta- or Kappa-opioid receptors and their subtypes as pharmacological tools and ii) opioid compounds with mixed agonist/antagonist profiles for possible therapeutic applications. To reach these goals, we use an interdisciplinary approach incorporating organic synthesis, peptide chemistry, extensive pharmacological characterization and conformational studies. Specific Aim 1 is based on our recent discovery that substitution of 3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid (Dhp) for the N-terminal tyrosine residue in opioid peptides produces antagonists at mu-, delta- or Kappa-receptors. We will synthesize Dhp analogues for Tyr1 replacement in opioid peptides that are capable of engaging in a variety of potential hydrophobic or hydrogen-bonding interactions with receptor moieties, with the expectation of obtaining more potent antagonists or inverse agonists, or compounds with a mixed K agonist/u antagonist profile. In Specific Aim 2 we will substitute the Dhp analogues developed in Specific Aim 1 for Tyr1 in known selective Kappa-, delta- or mu-agonist opioid peptides to convert them into antagonists or inverse agonists with selectivity for Kappa-, delta- or mu-receptors and their subtypes. In Specific Aim 3 we will develop potent K opioid antagonists or inverse agonists through structural modification of the cyclic tetrapeptide c[Phe-D-Pro-Phe-(D,L)-Trp] (CJ-15,208) recently isolated from the fungus Ctenomyces serratus. In Specific Aim 4 we will identify opioid peptide analogues containing certain Dhp analogues developed under Specific Aim 1 that have a mixed K agonist/mu antagonist profile as potential agents for the treatment of cocaine abuse. Specific Aim 5 concerns the development of chimeric opioid peptides with a mixed mu agonist/delta antagonist profile as analgesics with a low propensity to produce tolerance and dependence. The in vitro opioid activity profiles will be determined by performing opioid receptor binding assays, the guinea pig ileum and mouse vas deferens assays, and the [35S]GTPgammaS binding assay. The characterization of some of the compounds in vivo will include determination of the effects on cocaine discrimination and self-administration for the K agonist/mu antagonists and analgesic testing, including tolerance and dependence development, for the mixed mu agonist/delta antagonists. The conformation(s) of select compounds will be examined by 1HNMRspectroscopy in conjunction with theoretical conformational analyses.