[Expression and characterization of the FABP and Eg95 fusion gene from Echinococcus granulosus].
OBJECTIVE
To construct and express a fusion gene of fatty acid binding protein (FABP) with Eg95 which are protective antigen genes of Echinococcus granulosus, and investigate the immunological characteristics of the recombinant protein.


METHODS
Using cDNA fragments encoding FABP and Eg95 genes from E. granulosus Qinghai sheep strain as templates, a fusion gene FABP.Eg95 was amplified by asymmetric polymerase chain reaction th-rough a linking sequence encoding four glycine residues. The PCR products of fusion gene were subcloned into the pET28a (+) vector. The recombinant plasmid was transformed into Escherichia coli BL21 (DE3) cells and induced with IPTG. The recombinant protein was detected by SDS-PAGE and purified by Ni-IDA affinity chromatography, and its immunogenicity was analyzed by Western blotting. Results The fusion gene length was about 795 bp. Double enzyme digestion analysis and DNA sequencing confirmed that the fusion gene was cloned into pET-28a (+). The recombinant protein (Mr 31,000) was expressed in inclusion body in E. coli expression system, and was purified by Ni-IDA affinity chromatography. Western blotting analysis testified that the recombinant protein could be recognized by sera of cystic echinococcosis patients, but not by sera of healthy persons and schistosomiasis patients.


CONCLUSIONS
The FABP.Eg95 fusion gene has been constructed, and the purified recombinant protein has been confirmed with immunogenicity.
Experimental Center for Basic Medical Teaching, Sun Yat-sen University, Guangzhou 510080, China.
Ling
L
Wang
Hui-xia
HX
Hu
Su-xiang
SX
Zeng
Wei-hua
WH
Wu
Wen-jia
WJ
Gan
Li-ping
LP
Hu
Xu-chu
XC
Hu
D000818:Animals; D000947:Antigens, Helminth / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D018076:DNA, Complementary / Q000235:genetics; D048209:Echinococcus granulosus / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D015801:Helminth Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D012756:Sheep / Q000469:parasitology
D000947:Antigens, Helminth; D018076:DNA, Complementary; C446034:EG95 protein, Echinococcus granulosus; D050556:Fatty Acid-Binding Proteins; D015801:Helminth Proteins; D011993:Recombinant Fusion Proteins