کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1931179 | 1050543 | 2011 | 5 صفحه PDF | دانلود رایگان |

Non-toxic derivatives of botulinum neurotoxin A (BoNT/A) have potential use as neuron-targeting delivery vehicles, and as reagents to study intracellular trafficking. We have designed and expressed an atoxic derivative of BoNT/A (BoNT/A ad) as a full-length 150 kDa molecule consisting of a 50 kDa light chain (LC) and a 100 kDa heavy chain (HC) joined by a disulfide bond and rendered atoxic through the introduction of metalloprotease-inactivating point mutations in the light chain. Studies in neuronal cultures demonstrated that BoNT/A ad cannot cleave synaptosomal-associated protein 25 (SNAP25), the substrate of wt BoNT/A, and that it effectively competes with wt BoNT/A for binding to endogenous neuronal receptors. In vitro and in vivo studies indicate accumulation of BoNT/A ad at the neuromuscular junction of the mouse diaphragm. Immunoprecipitation studies indicate that the LC of BoNT/A ad forms a complex with SNAP25 present in the neuronal cytosolic fraction, demonstrating that the atoxic LC retains the SNAP25 binding capability of the wt toxin. Toxicity of BoNT/A ad was found to be reduced approximately 100,000-fold relative to wt BoNT/A.
Research highlights
► We used a non-toxic, recombinant BoNT/A ad as a model to study wt BoNT/A trafficking.
► We found that BoNT/A ad is 100,000 less toxic than wt BoNT/A in vivo.
► We found that BoNT/A ad does not cleave wt BoNT/A substrate SNAP25.
► We found that BoNT/A ad competes with wt BoNT/A for binding to receptors.
► We found that the light chain of BoNT/A ad forms a complex with SNAP25.
Journal: Biochemical and Biophysical Research Communications - Volume 405, Issue 4, 25 February 2011, Pages 673–677