Recombinant Listeria strains producing the nontoxic L-chain of botulinum neurotoxin A in a soluble form.

Fragments of Clostridium botulinum neurotoxin A (BoNT/A) gene (botA) were expressed in Listeria monocytogenes ATCC10527 to produce the L-chain of the toxin in a soluble form. A shuttle vector pAT19 (EmR) was used to make plasmid pAT-RL containing a botA gene fragment placed under C. botulinum ntnH-gene promoter control.

[Effective expression of fragments of a botulinum neurotoxin type A gene, coding for the L-chain and H-chain in E. coli, with formation of products causing protective immunity to administration of the toxin].

Native Clostridium botulinum gene coding for type A neurotoxin has been used to construct recombinant derivatives coding separately for L and H polypeptide chains of the toxin. The gene derivatives have been cloned into an expression vector pET28b in E. coli BL21 (DE3) cells.