Abstract
Botulinum neurotoxins (BoNTs) cause flaccid paralysis by inhibiting neurotransmission at cholinergic nerve terminals. BoNTs consist of three essential domains for toxicity: the cell binding domain (Hc), the translocation domain (Hn) and the catalytic domain (LC). A functional derivative (LHn) of the parent neurotoxin B composed of Hn and LC domains was recombinantly produced and characterised. LHn/B crystallographic structure at 2.8 angstrom resolution is reported. The catalytic activity of LHn/B towards recombinant human VAMP was analysed by substrate cleavage assay and showed a higher specificity for VAMP-1,-2 compared to VAMP-3. LHn/B also showed measurable activity in living spinal cord neurons. Despite lacking the Hc (cell-targeting) domain, LHn/B retained the capacity to internalize and cleave intracellular VAMP-1 and -2 when added to the cells at high concentration. These activities of the LHn/B fragment demonstrate the utility of engineered botulinum neurotoxin fragments as analytical tools to study the mechanisms of action of BoNT neurotoxins and of SNARE proteins.
Original language | English |
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Pages (from-to) | 52-57 |
Number of pages | 6 |
Journal | Journal of Structural Biology |
Volume | 174 |
Issue number | 1 |
DOIs | |
Publication status | Published - Apr 2011 |
Keywords
- protein engineering
- botulinum neurotoxin
- crystal structure
- SNARE