High throughput cryo-EM provides structural understanding for modulators of the lysosomal ion channel TRPML1

Access to high-resolution structural data for protein-ligand complexes is a prerequisite for structure-based medicinal chemistry, where the ability to iterate cycles of design-structure-redesign is highly desirable. For proteins refractory to X-ray crystallography, such as integral membrane proteins, enablement of high throughput structure determination by cryoelectron microscopy (cryo-EM) has the potential to be transformational for structure-based design. We have applied such an approach to the lysosomal ion channel transient receptor potential mucolipin 1 (TRPML1) in complex with ten chemically diverse modulators, both agonists and antagonists. The resulting depth of high-resolution structural data generated provides important insights into protein-ligand structure-function relationships, including mechanistic understanding of ligand-induced channel pore opening and closing. Moreover, the knowledge gained has the potential to support iterative design cycles toward improved modulators of this important biological target.