Dawbarn D, Fahey M, Watson J, Tyler S, Shoemark D, Sessions R, Zhang R, Brady L, Willis C, Allen S J
Department of Medicine, University of Bristol, Bristol BS1 3NY, UK.
Biochem Soc Trans. 2006 Aug;34(Pt 4):587-90. doi: 10.1042/BST0340587.
Biochemical studies have shown that domain 5 of the TrkA (tropomyosin receptor kinase A) receptor is involved in the binding of NGF (nerve growth factor). Crystallographic studies have confirmed this, demonstrating that one homodimer of NGF binds to two TrkAd5 molecules. TrkAd5 has been made recombinantly in Escherichia coli, purified and shown to bind NGF with picomolar affinity. We have used the co-ordinates of the crystal structure of the NGF-TrkAd5 complex to screen approximately two million compounds in silico for the identification of small molecule agonists/antagonists. Selected hits were shown to be active in an in vitro ligand-binding assay; structure-activity relationships are now being investigated. In addition, TrkAd5 has been shown to be efficacious in preclinical models of inflammatory pain and asthma by the sequestration of excess levels of endogenous NGF, and therefore represents a novel therapeutic agent.
生化研究表明，酪氨酸激酶受体A（TrkA）的第5结构域参与神经生长因子（NGF）的结合。晶体学研究证实了这一点，表明一个NGF同型二聚体与两个TrkA第5结构域分子结合。TrkA第5结构域已在大肠杆菌中重组制备、纯化，并显示出以皮摩尔亲和力结合NGF。我们利用NGF-TrkA第5结构域复合物的晶体结构坐标在计算机上筛选了约200万种化合物，以鉴定小分子激动剂/拮抗剂。所选的命中化合物在体外配体结合试验中显示出活性；目前正在研究构效关系。此外，通过隔离内源性NGF的过量水平，TrkA第5结构域已在炎症性疼痛和哮喘的临床前模型中显示出疗效，因此代表了一种新型治疗剂。
