Expression and Purification of Immuno-Dominant Peptide Derived From gp46-II for Detection of HTLV-II Specific Antibodies

Background K55 is a fusion protein that includes His-GST and a44 amino acid peptide derived from a conserved region of gp46-II of human T-cell leukemia virus (HTLV)-II. This protein is used in the detection of HTLV-II infection. Objectives In this study, we described the expression and purification of K55as a soluble form in Escherichia coli cells. Materials and Methods Synthetic DNA encoding K55 was sub-cloned into pGEX-4t-1 expression vector and then transformed into chemically competent E. coli cells. The expression of K55 was induced using 1 mM IPTG. The expression and solubility of K55 was evaluated by SDS-PAGE. The recombinant protein was purified using affinity chromatography. The immune reactivity of purified protein with antibodies present in infected serum was evaluated using ELISA. Results The SDS-PAGE results indicated that K55 is expressed as a soluble form in E. coli cells. In addition, ELISA results indicated that this protein interacts with anti-HTLV-II-specific antibodies in a concentration-dependent manner. Conclusions The K55 prepared in E. coil cells specifically reacts with anti-HTLV-II antibodies and could be used in the preparation of diagnostic reagents.