8HKH

Crystal structure of the LC/A1-DARPin18 complex

Summary for 8HKH

• Entry DOI: 10.2210/pdb8hkh/pdb
• Descriptor: BoNT/A, Designed ankyrin repeat protein 18, ZINC ION, ... (4 entities in total)
• Functional Keywords: botulinum neurotoxin, darpin, catalytic domain, toxin
• Biological source: Clostridium botulinum; More
• Total number of polymer chains: 4
• Total formula weight: 132718.27

Authors

Wu, Y.,Leka, O.,Kammerer, R. (deposition date: 2022-11-26, release date: 2023-11-29, Last modification date: 2025-01-01)

Primary citation

Leka, O.,Wu, Y.,Zanetti, G.,Furler, S.,Reinberg, T.,Marinho, J.,Schaefer, J.V.,Pluckthun, A.,Li, X.,Pirazzini, M.,Kammerer, R.A.
A DARPin promotes faster onset of botulinum neurotoxin A1 action.
Nat Commun, 14:8317-8317, 2023

PubMed Abstract: In this study, we characterize Designed Ankyrin Repeat Proteins (DARPins) as investigative tools to probe botulinum neurotoxin A1 (BoNT/A1) structure and function. We identify DARPin-F5 that completely blocks SNAP25 substrate cleavage by BoNT/A1 in vitro. X-ray crystallography reveals that DARPin-F5 inhibits BoNT/A1 activity by interacting with a substrate-binding region between the α- and β-exosite. This DARPin does not block substrate cleavage of BoNT/A3, indicating that DARPin-F5 is a subtype-specific inhibitor. BoNT/A1 Glu-171 plays a critical role in the interaction with DARPin-F5 and its mutation to Asp, the residue found in BoNT/A3, results in a loss of inhibition of substrate cleavage. In contrast to the in vitro results, DARPin-F5 promotes faster substrate cleavage of BoNT/A1 in primary neurons and muscle tissue by increasing toxin translocation. Our findings could have important implications for the application of BoNT/A1 in therapeutic areas requiring faster onset of toxin action combined with long persistence.

PubMed: 38110403
DOI: 10.1038/s41467-023-44102-4

Experimental method

X-RAY DIFFRACTION (2.7 Å)