8HKH image
Deposition Date 2022-11-26
Release Date 2023-11-29
Last Version Date 2025-01-01
Entry Detail
PDB ID:
8HKH
Keywords:
Title:
Crystal structure of the LC/A1-DARPin18 complex
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.70 Å
R-Value Free:
0.30
R-Value Work:
0.26
R-Value Observed:
0.26
Space Group:
P 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:BoNT/A
Chain IDs:A, B
Chain Length:436
Number of Molecules:2
Biological Source:Clostridium botulinum
Polymer Type:polypeptide(L)
Molecule:Designed ankyrin repeat protein 18
Chain IDs:C, D
Chain Length:149
Number of Molecules:2
Biological Source:synthetic construct
Ligand Molecules
Primary Citation
A DARPin promotes faster onset of botulinum neurotoxin A1 action.
Nat Commun 14 8317 8317 (2023)
PMID: 38110403 DOI: 10.1038/s41467-023-44102-4

Abstact

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.

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Primary Citation of related structures