Prokaryotic Expression and Antigenic Analysis of Wbkc Gene from Brucella abortus

[ Objective ] This study aimed to clone and express formyltransferase （Wbkc） gene from Brucella abortus in E. coli, purify the expressed protein and analyze its immunogenicity. [Method] A gene encoding 27 -35 ku formyltransferase （Wbkc） was amplified from the genomic DNA of BruceUa abortus by PCR. The amplified fragments were digested with BamH I and Sal I, and inserted into pET28a vector. The constructed recombinant plasmid pET 28a-Wbkc was trans- formed into E. coli BL21 and was induced to express the fusion protein. Subsequently, the protein was purified by histidine-binding resin column chromatography, and the immunogenicity was detected by Western blot assay. The recombinant plasmid was identified by colony PCR, double digestion and sequencing analysis. [ Result] Wbkc was successfully cloned and expressed in E. coli. A specific protein band of 29 ku was detected by SDS-PAGE. Western blot showed specific im- munoreactivity of the purified fusion protein. [ Conclusion] This study provided a solid foundation for further investigating diagnostic proteins for brucellosis and developing Brucella gene-deletion vaccines.

Plasma functionalized MoSe2 for efficient nonenzymatic sensing of hydrogen peroxide in ultra-wide pH range

Enzymatic sensors have inherent problems such as the low stability and limited pH range in industrial and biomedical applications and therefore,more efficient nonenzymatic sensors are highly desirable.Herein,plasmafunctionalized defective MoSe_(2)is prepared and studied as a highly efficient catalyst for electrochemical sensing of H_(2)O_(2).Experiments and theoretical computations show that the plasma-induced Se multi-vacancies and nitrogen dopants generate new active sites,expose more edge active surfaces,narrow the bandgap,and strengthen binding with the·OH intermediate,which imparts new fundamental knowledge about the roles of defects in catalysis.The defective MoSe_(2)-catalyzed sensor delivers competitive performance in hydrogen peroxide detection such as a low detection limit of 12.6 nmol/L,wide operational pH range of 1−13,good long-term stability,and high selectivity.The portable sensor produced by screen printing confirms the excellent commercial potential and in addition,the results not only reveal a novel concept to design and fabricate high-performance sensors for H_(2)_(O2)but also provide insights into the effectiveness of surface modification of diverse catalytic materials.