TREM2 has been identified by genomic analysis as a potential and novel target for the treatment of Alzheimer's disease. To enable structure-based screening of potential small molecule therapeutics, we sought to develop a robust crystallization platform for the TREM2 Ig-like domain. A systematic set of constructs containing the structural chaperone, maltose binding protein (MBP), fused to the Ig domain of TREM2, were evaluated in parallel expression and purification, followed by crystallization studies. Using protein crystallization and high-resolution diffraction as a readout, a MBP-TREM2 Ig fusion construct was identified that generates reproducible protein crystals diffracting at 2.0 Å, which makes it suitable for soaking of potential ligands. Importantly, analysis of crystal packing interfaces indicates that most of the surface of the TREM2 Ig domain is available for small molecule binding. A proof of concept co-crystallization study with a small library of fragments validated potential utility of this system for the discovery of new TREM2 therapeutics.

TREM2 已通过基因组分析确定为治疗阿尔茨海默病的潜在新靶点。为了能够对潜在的小分子疗法进行基于结构的筛选，我们试图为 TREM2 Ig 样域开发一个强大的结晶平台。在平行表达和纯化中评估了一组系统的构建体，该构建体包含与 TREM2 的 Ig 结构域融合的结构伴侣麦芽糖结合蛋白 (MBP)，然后进行结晶研究。使用蛋白质结晶和高分辨率衍射作为读数，确定了 MBP-TREM2 Ig 融合构建体，该构建体可产生可重现的蛋白质晶体，在 2.0 Å 处衍射，这使其适用于潜在配体的浸泡。重要的，晶体堆积界面的分析表明，TREM2 Ig 结构域的大部分表面可用于小分子结合。使用小型片段库进行的概念共结晶研究验证了该系统在发现新的 TREM2 疗法方面的潜在效用。