Abstract
Amyotrophic Lateral Sclerosis (ALS) is a devastating and progressive neurodegenerative disease with a complex, multifactorial pathophysiology, culminating in death of motor neurons. We introduce a new mechanism of ALS pathogenesis via study of a novel drug-like small molecule series that targets a subset of protein disulfide isomerase (PDI) within a previously largely unappreciated transient and energy-dependent multi-protein complex enriched for proteins of the ALS interactome. This drug, found by a novel phenotypic screen, has activity in cellular models for both familial and sporadic ALS, as well as in transgenic worms, flies, and mice bearing a diversity of human genes with ALS-associated mutations. The hit compound was initially identified as a modulator of human immunodeficiency virus (HIV) capsid assembly in cell-free protein synthesis and assembly (CFPSA) systems, with demonstrated antiviral activity against infectious HIV in cell culture. Its advancement for ALS-therapeutics, subsequent separation of activity against HIV and ALS into separate chemical subseries through structure-activity-relationship (SAR) optimization, and identification of the drug target by affinity chromatography as shown here, may provide insights into the molecular mechanisms governing pathophysiology of disordered homeostasis relevant to ALS.
Keywords
Affinity chromatography, Allostery, Molecular neuroscience, Neuro-degeneration, Phenotypic screen, Photocrosslinking, Protein assembly, Small molecule drug discovery, Structure activity relationship, Translational neuroscience