Co-expression of theBordetella pertussisleader peptidase I results in enhanced processing and expression of the pertussis toxin S1 subunit inEscherichia coli

Abstract

Bordetella pertussis is the causative agent of whooping cough. Traditional vaccines against this disease are inherently reactogenic, thus research is currently focussed on the production of less reactive, acellular vaccines. Expression of candidate antigens for these vaccines in Escherichia coli would be preferable, however, several B. pertussis antigens undergo incorrect post-translational processing in E. coli. The leader peptidase gene (lep) of B. pertussis encodes a protein of 294 amino acid residues that shares homology with other prokaryote leader peptidase I sequences. Hydrophilicity analysis based on the predicted amino acid sequence has demonstrated a similar membrane topology to that of E. coli and Salmonella typhimurium leader peptidase I. Co-expression of the B. pertussis lep gene in E. coli strain TOPP2 expressing the pertussis toxin S1 subunit was found to markedly increase the expression and post-translational processing of the S1 protein.

Cellular Engineering of Escherichia coli for the Enhanced Protein Production by Fermentation

“…The combination of signal peptide and mature protein can affect their secondary/tertiary structure of fusion protein which may facilitate or prevent the translocation of recombinant proteins across the membrane. Therefore, the following strategies are often considered for the efficient translocation and proper processing: (i) co-expression of molecular chaperone such as DnaKJ and GroELS (67), (ii) co-expression of proteins participating in membrane-transport process including SecB (68), (iii) co-expression of signal peptidase (69), (iv) the use of E. coli mutant such as />r/F-deficient strain (70), and (v) the use of fusion partner including DsbA and thioredoxin (71,72).…”