Prevention of aggregation and autocatalysis for sustaining biological activity of recombinant BoNT/A-LC upon long-term storage

Protein aggregation during expression,purification,storage,or transfer into requisite assay buffers hampers the use of proteins for in vitro studies. the formation of these aggregates represents a major obstacle in the study of biological activity and also restricts the spectrum of protein products being available for the biomedical applications. the catalytic light chain of botulinum neurotoxin type a undergoes autocatalysis and aggregation after purification upon long-term storage and freeze-thawing. in present study the conditions for the high level expression and purification of biologically active light chain protein of botulinum neurotoxin were optimized from a synthetic gene. several co-solvents were screened in order to prevent autocatalysis and aggregation of rbont/a-lc. the effect of the co-solvents is studied on endopeptidase activity during long term storage of the recombinant protein. the purified rbont/a-lc was also evaluated for its immunogenicity. © 2011 bentham science publishers.