[Research on TALF expression in Escherichia coli].

The expression of cDNA encoding Tachyleus auti-lipoposaccharide (LPS) factor, which is of interest for use as a potential inhibitor of the common core subunit of Gram-negative bacterial endotoxin. First, the TALF gene was inserted into expression vectors pGEX-4T-2, pET22b and pET28a to construct recombinant expression plasmids. The recombinant plasmids were transformed to E. coli BL21 (DE3) and the expression of TALF was examined. Results show that TALF in pET22b and pET28a vectors can't be expressed. Only the fusion protein GST-TALF was expressed in E. coli BL21 existing as inclusion bodies. From 1 liter of culture, about 4mg of fusion protein GST-TALF with 91% purity was finally obtained. No apparent bactericidal activity and LPS neutralizing activity of the fusion protein GST-TALF were found. After digested with thrombin, the fusion protein GST-TALF exhibited strong bactericidal activity and LPS neutralizing activity.