Expression, purification and comparative characterisation of enzymatically deactivated recombinant botulinum neurotoxin type A

Botulinum Neurotoxin (BoNT) is responsible for botulism, a severe and often deadly disease. Light chain of BoNT behaves as endopeptidase, cleaving the SNARE proteins, and inhibits the neurotransmitter release. A double-mutant E224A/E262A full-length BoNT Type A was successfully cloned and expressed in E. coli. The purified protein lacks the endopeptidase activity involved in the toxic action, and is structurally compatible with the native BoNT/A. Thus this molecule not only can be used as a safe surrogate for study of BoNT, but also can be potentially used as an antidote against botulism, and as a vaccine candidate for botulism.