DEVELOPMENT OF RECEPTOR-SPECIFIC OPIOID PEPTIDE ANALOGS

描述（由申请人提供）：我们建议合成有效的，稳定的和生物可利用的阿片肽类似物，设计成i)拮抗剂或反受体激动剂，具有高选择性的mu-， delta-或kappa -阿片受体及其亚型作为药理学工具，ii)混合激动剂/拮抗剂的阿片化合物，可能用于治疗应用。为了达到这些目标，我们采用跨学科的方法，结合有机合成，肽化学，广泛的药理学表征和构象研究。特异性目标1是基于我们最近的发现，3-（2,6-二甲基-4-羟基苯基）丙酸（Dhp）取代阿片肽n端酪氨酸残基，在mu-， delta-或kappa -受体上产生拮抗剂。我们将合成阿片肽中Tyr1替代的Dhp类似物，这些类似物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逆激动剂，或混合K激动剂/u拮抗剂的化合物。在Specific Aim 2中，我们将用在Specific Aim 1中开发的Dhp类似物替代已知选择性Kappa-、delta-或mu-激动剂阿片肽中的Tyr1，将其转化为具有Kappa-、delta-或mu-受体及其亚型选择性的拮抗剂或逆激动剂。在Specific Aim 3中，我们将通过对最近从真菌Ctenomyces serratus中分离到的环四肽c[ph -D- pro - phe -(D，L)- trp] （CJ-15,208）进行结构修饰，开发有效的K类阿片拮抗剂或逆激动剂。在Specific Aim 4中，我们将确定含有特定Dhp类似物的阿片类肽类似物，这些类似物在Specific Aim 1下开发，具有混合K激动剂/mu拮抗剂的特征，可作为治疗可卡因滥用的潜在药物。特定目标5关注嵌合阿片肽的发展，具有混合激动剂/拮抗剂的特征，作为低倾向产生耐受性和依赖性的镇痛药。体外阿片活性谱将通过阿片受体结合试验、豚鼠回肠和小鼠输精管试验以及[35S]GTPgammaS结合试验来确定。一些化合物的体内表征将包括确定K激动剂/拮抗剂对可卡因辨别和自我给药的影响，以及对混合mu激动剂/拮抗剂的镇痛试验，包括耐受性和依赖性的发展。选定化合物的构象将通过核磁共振光谱结合理论构象分析进行检查。

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.