Small Molecule Inhibitors of ZAP-70 for the Treatment of Autoimmune Disorders

描述(申请人提供)：ZAP-70是一种细胞质蛋白酪氨酸激酶，在T细胞抗原受体(TCR)信号转导和T细胞生物学的大多数方面发挥关键作用。ZAP-70是治疗普遍存在的人类T细胞依赖性自身免疫性疾病(如类风湿性关节炎、狼疮、多发性硬化症、银屑病)和同种异体移植的有吸引力的靶点。以前已经花费了大量的努力来开发特定的ZAP-70催化位点抑制剂，但没有成功，这可能是由于激酶催化结构域的特殊结构属性所致。在TCR刺激后，ZAP-70串联的SH2结构域与位于TCR的CD3和Zeta链细胞质结构域的保守序列基序(称为ITAM)内的双酪氨酸磷酸化残基相关联。对全长ZAP-70的诱变和结构研究表明，在与ITAM结合之前，ZAP-70以自抑制构象存在，其中串联的SH2结构域稳定了激活域的非活性构象。 这一建议是建立在Kuriyan和Weiss实验室在NIAMS资助的2009年ARRA Grand Opportunity赠款中所做的努力的基础上的，该项目旨在确定稳定ZAP-70的自抑制构象并作为该激酶的变构抑制剂的小分子。这一成功的研究计划导致了一系列特定的生化工具的开发，用于识别ZAP-70的原型变构抑制剂，并有望在T细胞调节方面进行专门的新药发现工作。在目前的提案中，由John Kuriyan、Art Weiss和Michael Weiss创立的一家新兴生物制药公司Nurix Inc.旨在通过优化ZAP-70的变构抑制剂的效力来扩展这一早期工作，这可能会作为一种新的T细胞特异性免疫抑制剂的临床开发的先导。该计划将(I)利用结晶学和其他生物物理技术深入了解这些小分子抑制剂与ZAP-70的相互作用模式，以促进铅的优化，以及(Ii)在已建立的T细胞功能模型中检查变构抑制剂化合物的活性。

DESCRIPTION (provided by applicant): ZAP-70 is a cytoplasmic protein tyrosine kinase that plays a critical function in T cell antigen receptor (TCR) signaling and in most aspects of T cell biology. ZAP-70 is an attractive therapeutic target for treatment of prevalent human T-cell dependent autoimmune diseases (e.g. rheumatoid arthritis, lupus, multiple sclerosis, psoriasis) and in allogenic transplantation. Considerable effort has previously been expended to develop specific ZAP-70 catalytic site inhibitors, without success, likely due to specific structural attributes of the kinase catalytic domain. Following TCR stimulation, the ZAP-70 tandem SH2 domains associate with dual tyrosine phosphorylated residues located within conserved sequence motifs (referred to as ITAMs) of the cytoplasmic domains of the CD3 and zeta chains of the TCR. Mutagenesis and structural studies on full-length ZAP-70 have shown that, prior to association with the ITAMs, ZAP-70 exists in an autoinhibited conformation in which the tandem SH2 domains stabilize an inactive conformation of the kinase domain. This proposal is built on the effort of the Kuriyan and Weiss labs in an NIAMS-funded 2009 ARRA Grand Opportunity grant to identify small molecules that stabilize the autoinhibited conformation of ZAP-70 and serve as allosteric inhibitors of the kinase. That successful research program led to development of a series of specific biochemical tools for identifying prototypical allosteric inhibitors of ZAP-70, and is poised to enable a dedicated new drug discovery effort in T cell regulation. In this current proposal, Nurix Inc., an emerging biopharmaceutical company founded by John Kuriyan, Art Weiss and Michael Rape, aims to extend this earlier work by optimizing the potency of allosteric inhibitors of ZAP-70 that could serve as a leads for clinical development of a new T-cell specific immunosuppressant. The program will (i) seek insight into the mode of interaction of these small molecule inhibitors with ZAP-70 using crystallographic and other biophysical techniques to facilitate lead optimization, and (ii) examine the activity of allosteric inhibitor compounds in established models of T cell function.