ABSTRACT
Background: Type 4 pili [T4P] is an important virulence factor of Pseudomonas aeruginosa [P. aeruginosa]. T4P pass the outer membrane through a large oligomeric channel made of a single PilQ protein that is most highly conserved at their C-termini. To develop a functional vaccine that can be used in clinical application, the secretin domain of the PilQ [PilQ380-706] was produced as a recombinant protein
Methods: A 981 bp fragment of C-terminal of the pilQ secretin [pilQ1138-2118] from was designed into the prokaryotic expression vector pET28a. The presence of the pilQ1138-2118 gene in the recombinant construct [pET28a/pilQ] was assessed by double digestion and PCR. After transformation, expression of the recombinant PilQ was induced by addition of IPTG. The expressed recombinant protein was purified by a modified method using a HisTrap affinity column and finally confirmed by SDS-PAGE. The functional activities of the produced PilQ380-706 confirmed by Western blot analysis and twitching inhibition assay
Results: The PCR and enzymatic digestion results showed the presence of the pilQ1138-2118 gene in the construct. The protein electrophoresis showed that the molecular weight of the recombinant PilQ380-706 is approximately 37 kDa. The Western blot analysis confirmed the specificity of specific IgG against the PilQ380-706 protein. The PilQ380-706 protein showed high biological activity in all of these standard assays
Conclusion: Since, the PilQ380-706 protein plays an important role in the biogenesis of pili; and thus, the primary establishment of P. aeruginosa; it seems that it can be used as a candidate vaccine or an adjuvant in the future studies