Construction, Expression Of Three Truncated PET41a-Em18 Prokaryotic Plasmid And Its Primary Antigenic Analysis

Objective: To clone, construct and expression three truncated pET41a-Em 18.1, pET41a-Em18.2, pET41a-Em18.3 recombinant plasmids and to study its primary antigenicity. Methods: The primers of three truncated Em18 were designed by DNAman biosoftware and these truncated fragments were amplified by PCR from pMD18-T/Em18, and were cloned into prokaryotic expression plasmid pET41a to construct the pET41a-Eml8-l,-2,-3, respectively. The recombinant plasimids were analyzed by sequenceing. The rEm18.(1, 2, 3)-GST fusion protein were expressed by induction with IPTG and purified using His-tag column, and then were detected by Western Blot and ELISA. Results: The pET41a-Em 18-1, -2,-3 positive clones were the exact recombinant plasmids and the expressed rEm18.(1, 2, 3)-GST recombinant proteins can be detected as a band of 41KDa, 45.5KDa and 45.5KDa by SDS-PAGE and Western blot result confirmed that these three recombinant proteins could specifically react with the serum samples from patients with alveolar echinococcosis (AE), respectively.Serological evaluation by ELISA was carried out using sera from 56patients with alveolar echinococcosis, 88with cystic echinococcosis, 24with hepatocirrhosis, 24with other disease, 6with lung fluke,6with liver fluke,6with schistosomiasis,6with cysticercosis and 24 from healthy persons.The results showed an overall sensitivity of 19.6% and 73.2% with rEm18.(1, 2)-GST for AE sera,specifiency 98.9% and 98.3%, positive predictive value 84.6% and 93.2%, negative predictive value...