Figure 1
From: Long-acting antibody ligand mimetics for HER4-selective agonism
ALM design and characterization. (A) Unliganded structure of HER4 receptor ECD (PDB ID: 2AHX) shows the separation between domain 1 and domain 2 and a buried dimerization arm (blue). (B) Structure of neuregulin-bound HER4 (PBD ID: 3U7U) shows that NRG1 engage a receptor conformational change to form a binding interface with domains 1 and 2. Vertical 90-degree rotation shows the extended dimerization arm (blue). (C) Structural model of ALM designs, using the b12 antibody as the scaffold (PBD ID: 1HZH) and NRG1 (PDB ID: 3U7U). (D) The variable heavy-chain CDR3 loop was replaced with ligand sequences. (E) SEC-MALS analysis confirmed homogeneity of ALM6 after protein A chromatography purification, with the molecular size calculated from MALS. (F) SEC traces of ALM6 at 0.5 mg/mL (solid) and at 10 mg/mL (dashed). (G) HER2/HER4 dual-expressing HEK293 cell-based luciferase reporter assay showed a gradual increase in receptor activation from ALM3, ALM4, ALM5, and ALM6. (H) Phospho-AKT activation was measured on iPSC-derived cardiomyocytes. The PyMOL Molecular Graphics System, Version 2.4.0, Schrödinger, LLC. (https://pymol.org) was used to create the structural model images in (A–C).
