Cloning, Expression and Purification of Outer Membrane Secretin PilQ406-770 of Neisseria Meningitidis Serogroup B

authors:

avatar Fakhri Haghi 1 , avatar Shahin Najar Perayeh 1 , * , avatar Seyed Davar Siadat 2 , avatar Mehdi Mahdavi 3

Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modarres University, Tehran, IR Iran
Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, IR Iran
Department of Virology, Pasteur Institute of Iran, Tehran, IR Iran

how to cite: Haghi F, Najar Perayeh S, Siadat S D, Mahdavi M. Cloning, Expression and Purification of Outer Membrane Secretin PilQ406-770 of Neisseria Meningitidis Serogroup B. Arch Clin Infect Dis. 2010;5(4): 193-9. 

Abstract

Background:

Neisseria meningitidis is a major cause of bacterial septicemia and meningitis. Currently, there are no vaccines to prevent disease caused by strains of N. meningitidis serogroup B, since cross-reactivity of the serogroup B capsule with human tissue has hampered efforts to develop a reliable vaccine. PilQ is an antigenically conserved outer membrane protein which is essential for meningococcal pilus expression at the cell surface.

Materials and methods:

In the current study, we selected a 1095bp fragment of C-terminal of secretin pilQ and evaluated the immunogenicity of this recombinant fragment. This fragment was amplified by PCR from genomic DNA isolated from N. meningitidis serogroup B and cloned into the pET-28a expression vector. PilQ406-770 was overexpressed with IPTG and then affinity-purified by Ni2+-Sepharose resin. The recombinant PilQ406-770 was reacted with rabbit anti-N. meningitidis polyclonal antibody in western-blot analysis. Mice were immunized subcutaneously with purified rPilQ406-770 mixed with an equal volume of Freund's adjuvant and evaluated specific serum antibody responses.

Results:

Our results show pilQ406-770 cloned in pET28a vector, while the cloning of pilQ406-770 was confirmed by colony- PCR and enzymatic digestion. SDS-PAGE analysis showed that our constructed prokaryotic expression system pET28apilQ406- 770-BL21efficiently produces target recombinant protein with molecular weight of 43 kDa in the form of dissoluble inclusion body.

Conclusion:

Our results confirmed that a prokaryotic expression system for PilQ406-770 protein was successfully constructed.

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