Synthesis and evaluation of potential affinity labels derived from endomorphin-2
Synthesis and evaluation of potential affinity labels derived from endomorphin-2
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DOI：
10.1034/j.1399-3011.2003.00029.x
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发表时间：
2003-02-01
期刊：
影响因子：
--
通讯作者：
Aldrich, JV
中科院分区：
文献类型：
--
作者：
Choi, H;Murray, TF;Aldrich, JV
为了鉴定阿片受体潜在的基于肽的亲和标记，选择内吗啡肽-2 (Tyr-Pro-Phe-PheNH(2))（一种有效且选择性的 mu-阿片受体内源性配体）作为修饰的母肽。使用标准Fmoc-固相肽合成结合Fmoc-Phe(p-NHAparallel tooc)的掺入和对氨基的修饰来制备四肽类似物。将亲电基团异硫氰酸酯和溴乙酰胺引入到 Phe(3) 或 Phe(4) 的对位；还制备了相应的含游离胺肽用于比较。使用表达 mu 和 delta 阿片受体的中国仓鼠卵巢 (CHO) 细胞在放射性配体结合测定中评估带有亲和标记基团的肽及其游离胺类似物。对于 L 受体结合，Phe4 上的修饰比 Phe3 上的修饰具有更好的耐受性。在测试的类似物中，[Phe(P-NH2)(4)]endomorphin-2 对 mu 受体表现出最高的亲和力 (IC50 = 37 nm)。在含有亲和标记基团的肽中，Phe(p-NHCOCH2Br)(4) 类似物显示出最高的 mu 受体亲和力 (IC50 = 158 nm)。大多数化合物对δ受体的结合亲和力可以忽略不计，与母体肽相似。
In an attempt to identify potential peptide-based affinity labels for opioid receptors, endomorphin-2 (Tyr-Pro-Phe-PheNH(2)), a potent and selective endogenous ligand for mu-opioid receptors, was chosen as the parent peptide for modification. The tetrapeptide analogs were prepared using standard Fmoc-solid phase peptide synthesis in conjunction with incorporation of Fmoc-Phe(p-NHAparallel tooc) and modification of the p-amino group. The electrophilic groups isothiocyanate and bromoacetamide were introduced into the para position on either Phe(3) or Phe(4); the corresponding free amine-containing peptides were also prepared for comparison. The peptides bearing an affinity label group and their free amine analogs were evaluated in a radioligand-binding assay using Chinese hamster ovary (CHO) cells expressing mu- and delta-opioid receptors. Modification on Phe4 was better tolerated than on Phe3 for L-receptor binding. Among the analogs tested, [Phe(P-NH2)(4)]endomorphin-2 showed the highest affinity (IC50 = 37 nm) for mu-receptors. The Phe(p-NHCOCH2Br)(4) analog displayed the highest mu-receptor affinity (IC50 = 158 nm) among the peptides containing an affinity label group. Most of the compounds exhibited negligible binding affinity for delta-receptors, similar to the parent peptide.