Photochemically enhanced binding of small molecules to the tumor necrosis factor receptor-1 inhibits the binding of TNF-α
Photochemically enhanced binding of small molecules to the tumor necrosis factor receptor-1 inhibits the binding of TNF-α
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DOI：
10.1073/pnas.211178398
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发表时间：
2001-10-09
影响因子：
11.1
通讯作者：
Decicco, CP
中科院分区：
文献类型：
--
作者：
Carter, PH;Scherle, PA;Decicco, CP
肿瘤坏死因子α（TNF-α）与1型TNF受体（TNFRc 1）的结合在炎症中起重要作用。尽管生物制剂（抗体、可溶性受体）在治疗基于TNF的自身免疫性疾病方面取得了临床成功，但尚未开发出有效的小分子拮抗剂。我们的筛选化学库显示，N-烷基5-亚芳基-2-硫代-1，3-噻唑烷-4-酮是这种蛋白质-蛋白质相互作用的拮抗剂。经过化学优化，我们发现了IW 927，它可以有效地破坏TNF-α与TNFRc 1的结合（IC 50 = 50 nM），并阻断拉莫斯细胞中TNF刺激的I κ-B磷酸化（IC 50 = 600 nM）。该化合物不能与相关的细胞因子受体TNFRc 2或CD 40可检测地结合，并且在高达100 μ M的浓度下不显示任何细胞毒性。对该分子和相关分子的详细评估显示，这类化合物是“光化学增强”抑制剂，因为它们以弱亲和力可逆地结合TNFRc 1（约100）。40-100 μ M），然后通过光化学反应共价修饰受体。我们获得了与TNFRc 1结合的IV 703（IW 927的类似物）的晶体结构。这种结构清楚地表明，抑制剂的芳香环之一通过Ala-62的主链氮与受体共价连接，Ala-62是一种已经参与TNF-α与TNFRc 1结合的残基。当结合我们的抑制剂在避光条件下是可逆结合剂的事实时，晶体学的结果为合理设计TNF-α-TNFRc 1相互作用的非光反应性抑制剂提供了基础。
The binding of tumor necrosis factor alpha (TNF-alpha) to the type-1 TNF receptor (TNFRc1) plays an important role in inflammation. Despite the clinical success of biologics (antibodies, soluble receptors) for treating TNF-based autoimmune conditions, no potent small molecule antagonists have been developed. Our screening of chemical libraries revealed that N-alkyl 5-arylidene-2-thioxo-1,3-thiazolidin-4-ones were antagonists of this protein-protein interaction. After chemical optimization, we discovered IW927, which potently disrupted the binding of TNF-alpha to TNFRc1 (IC50 = 50 nM) and also blocked TNF-stimulated phosphorylation of I kappa -B in Ramos cells (IC50 = 600 nM). This compound did not bind detectably to the related cytokine receptors TNFRc2 or CD40, and did not display any cytotoxicity at concentrations as high as 100 muM. Detailed evaluation of this and related molecules revealed that compounds in this class are "photochemically enhanced" inhibitors, in that they bind reversibly to the TNFRc1 with weak affinity (ca. 40-100 muM) and then covalently modify the receptor via a photochemical reaction. We obtained a crystal structure of IV703 (a close analog of IW927) bound to the TNFRc1. This structure clearly revealed that one of the aromatic rings of the inhibitor was covalently linked to the receptor through the main-chain nitrogen of Ala-62, a residue that has already been implicated in the binding of TNF-alpha to the TNFRc1. When combined with the fact that our inhibitors are reversible binders in light-excluded conditions, the results of the crystallography provide the basis for the rational design of nonphotoreactive inhibitors of the TNF-alpha -TNFRc1 interaction.