To take advantage of further similarities with BACE-1 ligands in the PDB, we used pose filters to discard docked poses that differ from the binding modes observed in 2F3F, 4DPF and 4K8S. These pose filters act on specific chemical motifs that occur both in GC4 ligands and in these reference structures. The chemical motifs were identified manually by visual inspection, and the filtering process was automated using Python scripts and OpenBabel .