cloning and expression of pora gene as the first step of a vaccine candidate study against neisseria meningitidis serogroup a infection

introduction: neisseria meningitidis is a major causative agent of bacterial septicemia and meningitis in human. pora is a major component of the outer membrane of n. meningitidis and functions as a cationic porin. this study aimed to clone and determine the expression of pora as the first step for producing a proper antigen in a vaccine study against n. meningitidis. methods: an approximately 1200-bp fragment of pora gene was amplified by pcr using                  n. meningitidis serogroup a genomic dna and then cloned into prokaryotic expression vector pet-28a. the resulting construct (pet28a-pora plasmid) was transformed into competent e.coli bl21 cells for expression of recombinant protein. the proper overexpression of the recombinant protein was verified by sds-page and western blotting. results: cloning of pora was confirmed by colony-pcr and enzymatic digestion. the nucleotide sequence homology of the cloned pora gene was 97% , compared to the reference gene (ncbi genbank accession number al157959.1). the prokaryotic expression system (pet28a-pora- bl21) could  produce our 45-kda target recombinant protein, efficiently. conclusion: the prokaryotic expression system and conditions used in this study provides an applicable method for producing recombinant pora and possibly many other bacterial outer membrane proteins for future vaccine studies.