Structural studies of molecular cancer targets and drug development

目前正在研究作为校内合作的两个系统。生长因子受体结合蛋白2 (Grb2) SH2结构域与酪氨酸受体激酶（RTKs）的酪氨酸磷酸化细胞质结构域的高亲和力结合是许多类型癌症治疗干预的一个有吸引力的靶点。为此，我们确定了Grb2 SH2结构域和强效不含磷大环肽模拟物之间复合物的两种晶体形式的结构，该复合物对erbb -2依赖性乳腺癌具有显著的抗增殖作用。该药物代表了第二代抑制剂，与开链抑制剂相比，其结合亲和力和生物利用度大大提高。在2.0和1.8条件下，每个不对称单元分别有一个和两个交换结构域的二聚体。蛋白质和抑制剂之间的结合模式和特异性相互作用为这类大环化合物的高效提供了见解，并可能有助于进一步优化，作为迭代合理药物设计过程的一部分。我们还参与了一项多学科合作，以开发有效的和特异性的人类Chk2激酶抑制剂。我们在这个项目中的作用是确定Chk2与小分子抑制剂配合物的共晶结构。到目前为止，我们已经确定了8种不同化合物的共晶结构，这提供了关于抑制剂结合模式的丰富信息，并导致了如何提高特异性和效力的想法。我们还生产了位点特异性生物素化Chk2，用于抑制剂结合的表面等离子体共振研究。最后，我们确定了人类LRF的POZ结构域的结构，这是肿瘤发生的主要调节因子，作为开发该蛋白抑制剂的第一步。

Two systems are currently under study as intramural collaborations. The high-affinity binding of the growth-factor receptor-bound protein 2 (Grb2) SH2 domain to tyrosine-phosphorylated cytosolic domains of receptor tyrosine kinases (RTKs) is an attractive target for therapeutic intervention in many types of cancer. To this end, we have determined the structures of two crystal forms of a complex between the Grb2 SH2 domain and a potent non-phosphorus containing macrocyclic peptide mimetic that exhibits significant anti-proliferative effects against erbB-2-dependent breast cancers. This agent represents a second generation inhibitor with greatly improved binding affinity and bioavailability compared to its open-chain counterpart. The structures were determined at 2.0 and 1.8 with one and two domain-swapped dimers per asymmetric unit, respectively. The mode of binding and specific interactions between the protein and the inhibitor provide insight into the high potency of this class of macrocylic compounds and may aid in further optimization as part of the iterative rational drug design process. We are also involved in a multidisciplinary collaboration to develop potent and specific inhibitors of human Chk2 kinase. Our role in this project is to determine co-crystal structures of Chk2 in complex with small molecule inhibitors. Thus far we have determined 8 co-crystal structures with different compounds and this has provided a wealth of information about the mode of inhibitor binding and led to ideas about how to improve specificity and potency. We have also produced site-specifically biotinylated Chk2 for surface plasmon resonance studies of inhibitor binding. Finally, we have determined the structure of the POZ domain of human LRF, a master regulator of oncogenesis, as a first step toward the development of inhibitors of this protein (see Scientific Advances).