Ferrie John J, Lengyel-Zhand Zsofia, Janssen Bieneke, Lougee Marshall G, Giannakoulias Sam, Hsieh Chia-Ju, Pagar Vinayak Vishnu, Weng Chi-Chang, Xu Hong, Graham Thomas J A, Lee Virginia M-Y, Mach Robert H, Petersson E James
Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , PA 19104 , USA . Email:
Department of Radiology , Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , USA.
Chem Sci. 2020 Sep 10;11(47):12746-12754. doi: 10.1039/d0sc02159h. eCollection 2020 Dec 21.
Small molecules that bind with high affinity and specificity to fibrils of the α-synuclein (αS) protein have the potential to serve as positron emission tomography (PET) imaging probes to aid in the diagnosis of Parkinson's disease and related synucleinopathies. To identify such molecules, we employed an ultra-high throughput screening strategy using idealized pseudo-ligands termed exemplars to identify compounds for experimental binding studies. For the top hit from this screen, we used photo-crosslinking to confirm its binding site and studied the structure-activity relationship of its analogs to develop multiple molecules with nanomolar affinity for αS fibrils and moderate specificity for αS over Aβ fibrils. Lastly, we demonstrated the potential of the lead analog as an imaging probe by measuring binding to αS-enriched homogenates from mouse brain tissue using a radiolabeled analog of the identified molecule. This study demonstrates the validity of our powerful new approach to the discovery of PET probes for challenging molecular targets.
与α-突触核蛋白（αS）纤维具有高亲和力和特异性结合的小分子，有潜力作为正电子发射断层扫描（PET）成像探针，辅助帕金森病及相关突触核蛋白病的诊断。为了鉴定此类分子，我们采用了一种超高通量筛选策略，使用称为范例的理想化假配体来鉴定用于实验性结合研究的化合物。对于此次筛选中最突出的结果，我们利用光交联来确认其结合位点，并研究其类似物的构效关系，以开发出多种对αS纤维具有纳摩尔亲和力且对αS比对Aβ纤维具有适度特异性的分子。最后，我们通过使用所鉴定分子的放射性标记类似物测量其与来自小鼠脑组织的富含αS的匀浆的结合，证明了先导类似物作为成像探针的潜力。这项研究证明了我们强大的新方法对于发现针对具有挑战性的分子靶点的PET探针的有效性。
