Expression and purification of a fusion gene TSO45W-4B-TSOL18 of Taenia solium in Escherichia coli ArcticExpress(DE3) and preparation of rabbit antiserum / 中国地方病学杂志

ABSTRACT

Objective To construct a recombinant plasmid pGEX-TSO45W-4B-TSOL18 of Taenia solium,to obtain purified recombinant protein TSO45W-4B-TSOL18 and to prepare rabbit antiserum against the recombinant fusion protein.Methods TSO45W-4B and TSOL18 encoding genes were connected with hydrophobic (Gly4Ser)3 linker.TSO45W-4B-TSOL18 fusion gene was synthesized and cloned into an expression vector pGEX-1λT to construct a recombinant plasmid pGEX-TSO45W-4B-TSOL18.The positive recombinants were transformed into Escherichia(E.) coli ArcticExpress (DE3),and the expression of recombinant protein was induced with isopropylβ-D-thiogalactopyranoside (IPTG) and analyzed by sodium dodecyl sulfate polyacrylamide gelelectrophoresis (SDS-PAGE).The expressed recombinant fusion protein was purified through affinity chromatography.The purified recombinant protein was mixed with complete Freunds adjuvant at a dosage of 0.5 mg.Rabbit was intramuscularly and subcutaneously immunized in the hind leg and the back,respectively.After 2 weeks the rabbit was boosted with purified recombinant protein which was mixed with incomplete Freunds adjuvant at the same dosage.Rabbit can be boosted every 10 days until an adequate response was achieved.At the 6th day after the last immunization,blood was collected from the rabbit heart.Serum was separated to purify and prepare the antiserum.ELISA was applied to determine the titer of the antiserum and Western blot assay was used to determine the specificity of the antiserum.Results The size of the synthesized fusion gene TSO45W-4B-TSOL18 was 789 bp.The results of restriction enzyme digestion showed that the recombinant plasmid pGEX-TSO45W-4B-TSOL18 was successfully constructed.DNA sequencing showed that the size of the fusion gene TSO45W-4B-TSOL18 was 789 bp,which was consistent with expected result.As demonstrated by SDS-PAGE,relative molecular mass of the expressed recombinant fusion protein was approximately 55 × 103,and its purity was 85％ after purification with affinity chromatography.Titer of the antiserum against the recombinant protein was 1 ∶ 512 000 in ELISA assay and the specific rabbit antiserum against the purified recombinant protein TSO45W-4B-TSOL18 could specifically bind to the recombinant fusion protein in Western blot assay.The relative molecular mass of the specific band was about 55 × 103,which was consistent with expected size.Conclusions The recombinant plasmid pGEX-TSO45W-4BTSOL18 of Taenia solium is successfully constructed.High quality recombinant fusion protein TSO45W-4B-TSOL18 and high titer rabbit antiserum are successfully prepared.