Fig. 1
From: Reengineering anthrax toxin protective antigen for improved receptor-specific protein delivery
Ribbon representation of the structures of PA constructs shown in their activated/furin-cleaved PA63 version. a Previously published, retargeted PAm-Ac2 [10]. b–d Schematic representation of the prepore-to-pore conversion at the respective pH of furin-cleaved PAwt (b), PAm fused to a retargeting DARPin, PAm-Ac2 (c), and PAwt fused to the wild-type receptor domain and the retargeting DARPin, PAwt-sANTXR-Ac2 (d). e Newly designed stabilized PAwt-sANTXR-Ac2 with PAwt, the wild-type receptor CMG2 VWA domain, and the retargeting DARPin; PA shown in red, EpCAM-retargeting DARPin Ac2 shown in blue, CMG2 receptor VWA domain (sANTXR) shown in green, and prepore-stabilizing interaction region highlighted in black oval. Protein structures were adapted from PDB ID: 1TZN (PA prepore binding sANTXR), 1ACC (PA), and 4YDW (DARPin)