Cloning, expression and purification of truncated Chlamydia trachomatis outer membrane protein 2 (omp2) and its application in an ELISA assay.
Although a simple and direct method does not exist for the detection of chlamydial infections, there are situations in which reliable serological tests, with sensitivity related to a specific antigen, could be helpful.



The aim of this study was to clone the first 1100 bp of the C. trachomatis outer membrane protein 2 (omp2) gene in order to prepare a recombinant protein for use in an ELISA system designed to recognize the anti- C. trachomatis antibody in patient sera.



The PCR product of the chlamydial omp2 gene was cloned in pBluescript and its first 1100 bp was subcloned in the pQE-30 expression vector and induced by IPTG. The recombinant protein was purified by affinity chromatography and its purity was confirmed by SDS-PAGE, gel diffusion and western blot analyses. The purified protein was coated onto a polystyrene microplate and tested by ELISA using patient serum.



We have cloned, over-expressed and purified biologically functional recombinant truncated Omp2 from C. trachomatis for use, as a species-specific recognition antigen, in an ELISA system. In this study we determined a cut-off value of 0.345 for this ELISA system using 55 negative sera and measured six positive sera at dilutions of 1:20-1:2560.



As a species-specific recognition antigen, the over-expressed and purified recombinant truncated Omp2 from C. trachomatis performed well in an ELISA system.
Kazemi
Bahram
B
Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. bahram_14@yahoo.com
Seyed
Negar
N
Bandehpour
Mojgan
M
Sharifnia
Zarrin
Z
Pakzad
Parviz
P
D000907:Antibodies, Bacterial / Q000097:blood*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification*; D001483:Base Sequence; D002692:Chlamydia trachomatis / Q000235:genetics*; D016993:Chlamydophila pneumoniae / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; C063931:Omp2 protein, bacteria; D011994:Recombinant Proteins