Park See-Hyoung, Oh Hyun-Sik, Kang Mi-Ae, Cho Hyeongjin, Prasad Joshi Bishnu, Won Jonghwa, Lee Keun-Hyeung
Signal Transduction Laboratory, Mogam Biotechnology Research Institute, 341 Pojung-Ri, Koosung-Myun, Yongin-City, Kyunggi-Do, 449-910, Republic of Korea.
Bioorg Med Chem. 2007 Jun 1;15(11):3938-50. doi: 10.1016/j.bmc.2006.06.059. Epub 2007 Apr 5.
The antagonists for the SH2 domain are regarded as novel therapeutic candidates for cancer, autoimmune disease, and chronic inflammatory disease. Previously, we identified rosmarinic acid (alpha-o-caffeoyl-3,4-dihydroxyphenyl-lactic acid; RosA) from Prunella vulgaris as an antagonist for the p56lck SH2 domain by screening natural products. RosA not containing phosphotyrosine surrogate had a considerable inhibitory activity for T-cell antigen receptor (TCR)-induced interleukin (IL)-2 expression, and subsequent T-cell proliferation in vitro cell assay. To investigate the structure-activity relationship of RosA and to identify a novel p56lck SH2 antagonist with more potent in vitro T-cell inhibitory activity, we synthesized several analogs of RosA by using rational design. All synthesized compounds were tested in vitro binding activity for the SH2 domain and in vitro T-cell inhibitory activity. All four hydroxyl groups of RosA were essential for binding with the p56lck SH2 domain and T-cell inhibitory activity. Unexpectedly, conformationally less constrained analogs 4 and 9 showed a more potent binding affinity for the SH2 domain than that of RosA, and chirality of the analog did not play an important role in protein binding. We successfully identified several RosA analogs with a more potent T-cell inhibitory activity than that of RosA. Overall results revealed important structural requirements of the p56lck SH2 antagonists for in vitro T-cell inhibitory activity and in vitro protein binding activity.
SH2结构域拮抗剂被视为癌症、自身免疫性疾病和慢性炎症性疾病的新型治疗候选药物。此前，我们通过筛选天然产物，从夏枯草中鉴定出迷迭香酸（α - o - 咖啡酰 - 3,4 - 二羟基苯乳酸；RosA）作为p56lck SH2结构域的拮抗剂。不含有磷酸酪氨酸类似物的RosA在体外细胞实验中对T细胞抗原受体（TCR）诱导的白细胞介素（IL）-2表达以及随后的T细胞增殖具有显著的抑制活性。为了研究RosA的构效关系，并鉴定一种在体外T细胞抑制活性方面更有效的新型p56lck SH2拮抗剂，我们通过合理设计合成了几种RosA类似物。所有合成的化合物都进行了SH2结构域的体外结合活性和体外T细胞抑制活性测试。RosA的所有四个羟基对于与p56lck SH2结构域结合以及T细胞抑制活性都是必不可少的。出乎意料的是，构象限制较少的类似物4和9对SH2结构域的结合亲和力比RosA更强，并且类似物的手性在蛋白质结合中并不起重要作用。我们成功鉴定出了几种在体外T细胞抑制活性方面比RosA更强的RosA类似物。总体结果揭示了p56lck SH2拮抗剂在体外T细胞抑制活性和体外蛋白质结合活性方面的重要结构要求。
