Pargellis Christopher, Tong Liang, Churchill Laurie, Cirillo Pier F, Gilmore Thomas, Graham Anne G, Grob Peter M, Hickey Eugene R, Moss Neil, Pav Susan, Regan John
Department of Biology, Boehringer Ingelheim Pharmaceuticals, Research and Development Center, 900 Ridgebury Road, Ridgefield, Connecticut 06877, USA.
Nat Struct Biol. 2002 Apr;9(4):268-72. doi: 10.1038/nsb770.
The p38 MAP kinase plays a crucial role in regulating the production of proinflammatory cytokines, such as tumor necrosis factor and interleukin-1. Blocking this kinase may offer an effective therapy for treating many inflammatory diseases. Here we report a new allosteric binding site for a diaryl urea class of highly potent and selective inhibitors against human p38 MAP kinase. The formation of this binding site requires a large conformational change not observed previously for any of the protein Ser/Thr kinases. This change is in the highly conserved Asp-Phe-Gly motif within the active site of the kinase. Solution studies demonstrate that this class of compounds has slow binding kinetics, consistent with the requirement for conformational change. Improving interactions in this allosteric pocket, as well as establishing binding interactions in the ATP pocket, enhanced the affinity of the inhibitors by 12,000-fold. One of the most potent compounds in this series, BIRB 796, has picomolar affinity for the kinase and low nanomolar inhibitory activity in cell culture.
p38丝裂原活化蛋白激酶在调节促炎细胞因子（如肿瘤坏死因子和白细胞介素-1）的产生中起关键作用。阻断这种激酶可能为治疗多种炎症性疾病提供一种有效的疗法。在此，我们报告了针对人p38丝裂原活化蛋白激酶的一类高效且选择性的二芳基脲类抑制剂的一个新的变构结合位点。该结合位点的形成需要一种此前在任何蛋白丝氨酸/苏氨酸激酶中均未观察到的大的构象变化。这种变化发生在激酶活性位点内高度保守的天冬氨酸-苯丙氨酸-甘氨酸基序中。溶液研究表明这类化合物具有缓慢结合动力学，这与构象变化的需求一致。改善该变构口袋中的相互作用以及在ATP口袋中建立结合相互作用，可使抑制剂的亲和力提高12000倍。该系列中最有效的化合物之一BIRB 796对该激酶具有皮摩尔亲和力，在细胞培养中具有低纳摩尔抑制活性。
