Dutta A S, Gormley J J, Coath M, Hassall L, Hayward C F, Gellert P R, Kittlety R S, Alcock P J, Ferguson R, Halterman T, Jamieson A, Moors J A, Moores J M, Rees A, Wood L J, Reilly C F, Haworth D
AstraZeneca, Macclesfield, Cheshire, UK.
J Pept Sci. 2000 Aug;6(8):398-412. doi: 10.1002/1099-1387(200008)6:8<398::AID-PSC270>3.0.CO;2-1.
Additional structure-activity relationship studies on potent cyclic peptide inhibitors of very late antigen-4 (VLA-4) are reported. The new N- to C-terminal cyclic hexa-, hepta- and octapeptide inhibitors like cyclo(MeIle/MePhe-Leu-Asp-Val-X) (X = 2-4 amino acids containing hydrophobic and/or basic side chains) were synthesized using solid phase peptide synthesis methods. The peptides were evaluated in in vitro cell adhesion assays and in in vivo inflammation models. Many of the peptides like cyclo(MePhe-Leu-Asp-Val-D-Arg-D-Arg) (ZD7349) (17), cyclo(MeIle-Leu-Asp-Val-D-Arg-D-Arg-D-Phe) (20), cyclo(MeIle-Leu-Asp-Val-D-Arg-D-Arg-MePhe) (21) and cyclo(MePhe-Leu-Asp-Val-D-Arg-D-Arg-D-Ala-D-Ala) (23) were potent inhibitors of VLA-4-mediated cell adhesion and inhibited ovalbumin-induced delayed type hypersensitivity (DTH) response in mice. The more potent compounds were highly selective and did not affect U937 cell adhesion to fibronectin (VLA-5), phorbolmyristate acetate or PMA-differentiated U937 cell adhesion to intercellular cell adhesion molecule-1 (ICAM-1)-expressing Chinese hamster ovary cells (LFA-1) and adenosine diphosphate (ADP)-induced platelet aggregation (GPIIb/IIIa). In contrast to the inhibitors like Ac-cyclo(D-Lys-D-Ile-Leu-Asp-Val) and cyclo(CH2CO-Ile-Leu-Asp-Val-Pip-CH2CO-Ile-Leu-Asp-Val-Pip) described earlier, the new compounds were much more compatible with the depot formulations based on poly(DL-lactide-co-glycolide) polymers. The hexapeptide cyclo(MePhe-Leu-Asp-Val-D-Arg-D-Arg) (ZD7349) (17) inhibited MOLT-4 cell adhesion to fibronectin and vascular cell adhesion molecule-1 (VCAM-1) with IC50 values of 260 and 330 nM, respectively, and did not show any significant effect against other integrins (IC50 > 300 microM). ZD7349 inhibited ovalbumin-induced DTH response in mice when administered continuously using a mini-pump (ED50 0.01 mg/kg/day) or when given as an s.c. or i.v. bolus injection at a dose of 1-10 mg/kg. ZD7349 was also active in type II collagen-induced arthritis (CIA) and experimental autoimmune encephalomyelitis (EAE) tests at a dose of 3-10 mg/kg. The peptide was released from some formulations over a period of 10-20 days. ZD7349 is currently undergoing pre-clinical investigation.
报道了对极晚期抗原-4（VLA-4）强效环肽抑制剂的进一步构效关系研究。使用固相肽合成方法合成了新的N端至C端环六肽、环七肽和环八肽抑制剂，如环（甲基异亮氨酸/甲基苯丙氨酸-亮氨酸-天冬氨酸-缬氨酸-X）（X = 含疏水和/或碱性侧链的2 - 4个氨基酸）。这些肽在体外细胞黏附试验和体内炎症模型中进行了评估。许多肽，如环（甲基苯丙氨酸-亮氨酸-天冬氨酸-缬氨酸-D-精氨酸-D-精氨酸）（ZD7349）（17）、环（甲基异亮氨酸-亮氨酸-天冬氨酸-缬氨酸-D-精氨酸-D-精氨酸-D-苯丙氨酸）（20）、环（甲基异亮氨酸-亮氨酸-天冬氨酸-缬氨酸-D-精氨酸-D-精氨酸-甲基苯丙氨酸）（21）和环（甲基苯丙氨酸-亮氨酸-天冬氨酸-缬氨酸-D-精氨酸-D-精氨酸-D-丙氨酸-D-丙氨酸）（23），是VLA-4介导的细胞黏附的强效抑制剂，并能抑制小鼠卵清蛋白诱导的迟发型超敏反应（DTH）。更有效的化合物具有高度选择性，不影响U937细胞与纤连蛋白（VLA-5）的黏附、佛波酯肉豆蔻酸酯乙酸酯或PMA分化的U937细胞与表达细胞间细胞黏附分子-1（ICAM-1）的中国仓鼠卵巢细胞（LFA-1）的黏附以及二磷酸腺苷（ADP）诱导的血小板聚集（GPIIb/IIIa）。与之前描述的抑制剂如Ac-环（D-赖氨酸-D-异亮氨酸-亮氨酸-天冬氨酸-缬氨酸）和环（CH2CO-异亮氨酸-亮氨酸-天冬氨酸-缬氨酸-哌啶-CH2CO-异亮氨酸-亮氨酸-天冬氨酸-缬氨酸-哌啶）相比，新化合物与基于聚（DL-丙交酯-共-乙交酯）聚合物的长效制剂更相容。环六肽环（甲基苯丙氨酸-亮氨酸-天冬氨酸-缬氨酸-D-精氨酸-D-精氨酸）（ZD7349）（17）抑制MOLT-4细胞与纤连蛋白和血管细胞黏附分子-1（VCAM-1）的黏附，IC50值分别为260和330 nM，对其他整合素无显著影响（IC50 > 300 μM）。当使用微型泵持续给药（ED50 0.01 mg/kg/天）或皮下或静脉推注给药剂量为1 - 10 mg/kg时，ZD7349抑制小鼠卵清蛋白诱导的DTH反应。ZD7349在剂量为3 - 10 mg/kg时，在II型胶原诱导的关节炎（CIA）和实验性自身免疫性脑脊髓炎（EAE）试验中也有活性。该肽在10 - 20天内从一些制剂中释放出来。ZD7349目前正在进行临床前研究。
