猪传染性胃肠炎病毒n基因的原核表达及重组蛋白的免疫活性分析

A pair of primers containing BamHI and XhoI sites was designed to amplify n gene of 1149bp from the positive pMD18-TN plasmid of transmissible gastroenteritis virus n gene by PCR.PCR product was subcloned into multiple cloning sites of pET-30a containing 6 His·Tag.Recombinant plasmid pET-30a of n gene named pET30a-N was transfected into E.coli BL21 and the bacteria was induced with IPTG at 37℃.It was demonstrated by SDS-PAGE that recombinant N protein expressed in E.coli BL21 was soluble protein and its molecular weight was about 52kD.The result of Western blot test showed that immunoactivity of the recombinant N protein was the same to that of the natural N protein.

Purification and Immunocompetence Analysis of GP5 Protein in Porcine Reproductive and Respiratory Syndrome

[Objective] The purification and immunocompetence of GPS protein in porcine reproductive and respiratory syndrome (PRRS) were analyzed in this study, which provided basis for establishing the corresponding serological method. [Method] The recombinant expression plasmid pGEX-6P-5 was transformed into BL21 and expressed after being induced with IPTG. The solubility analysis of expression products was carried out, and then the recombinant protein was purified for SDS-PAGE identification and Western-blot analysis. Finally, the recombinant antigen was used in the immune experiment of guinea pigs. [Result] The target protein content accounted for 30% of the total cells protein content according to the chromatography scanning, and the purity of target protein after purification reached 80%. The purified protein was analyzed by Western-blot and immune experiment of guinea pigs, and the results showed that the expressed protein had good reactionogenicity and immunogenicity. [Conclusion] This study provides materials for further studies on the function between PRRSV ORF5 gene and its editing protein, which also lays a foundation for porcine reproductive and respiratory syndrome virus genetic engineering products.

Expression of Porcine Reproductive and Respiratory Syndrome Virus ORF7 Gene and Purification and Immunological Activity Analysis of the Recombinant Protein

[Objective] The aim of this study was to realize efficient expression of the porcine reproductive and respiratory syndrome virus （PRRSV） ORF7 gene in genetic engineering bacteria and analYze the immunological activity of the recombinant protein after purification. [ Method] The constructed recombinant expression vector pET-ORF7 was transformed into Escherichia co1BL21 （DE3） and induced by IPTG under the optimal condition. After analysis of SDS-PAGE and Western Blot, the expression products were purified by Ni-NTA His · Bind Resin chrom- atographic column under denaturing condition and renatured by gradient dialysis. Subsequently, the immunological activity of the renatured recombinant protein was detected by Westem Blot and indirect ELISA. [ Result] The recombinant plasmid pET-ORF7 expressed in E. coli successfully, and the fusion protein was in the form of inclusion body. By SDS-PAGE detection, the molecular weight of the expression protein was approximate 33 kD, according with the expectation. Analysis by Bandscan software showed that the expressed fusion protein was about 50% of total bacterial protein of BL21 （DE3）. Wastem Blot and indirect ELISA detection showed that the renatured protein could react with PRRSV positive serum specifically, indicating its good immunological activity. [ Conclusion] This study lays a foundation for the preparation of PRRSV monoclonal antibody and diagnostic kit.

Investigation of the Mutagenic Potential of Immunomodulator Arglabin Native in Tablets in the Ames Test

The mandatory preclinical safety evaluation is an essential prerequisite to obtain the qualitative and effective medicines. Due to the fact that drugs may reveal genotoxic properties, the investigation of their mutagenic activity is an obligatory part of the preclinical drug safety program. The aim of the research is to study mutagenic properties of a new original immunomodulator Arglabin native in tablets in the induced test of gene mutations （the Ames test） on Salmonella typhimurium strains. Materials and methods： Four strains of S. typhimurium TA98, TA100, TA1535, and TA1537 were used to assess the mutagenicity in the Ames test. Results and conclusions： No statistically reliable dose-dependent increase in the number of revertant colonies of Salmonella typhimurium has been observed in the presence of the given drug within the investigated dose ranges from 5.0 to 100.0 μg/mL for strains TA100 and TA1535, and from 5.0 to 250 μg/mL for strains TA98 and TA1537 against the baseline of spantaneous mutations. Arglabin native in tablets does not reveal a mutagenic activity within the studied dose ranges on Salmonella typhimurium strains TA98, TA100, TA1535, TA1537.