a simple method for high-level expression of htlv-1 gp46-i(162-214) peptide and its application for screening

Background: gp46-i(162-214) is a linear peptide derived from human t-lymphotropic virus type 1 (htlv-1) gp46-i envelope protein. this protein is commonly used to detect htlv-1 antibodies during enzyme-linked immunosorbent assay (elisa) or western blotting. objectives: this study reported a simple and efficient method for large-scale preparation of this peptide, which is employed for diagnostic purposes. methods: this study was a descriptive research. the dna encoding gp46-i(162-214) was optimized according to e. coli codon usage. it was then synthesized and sub cloned into a pgs21a vector. this vector added a his-gst tag to the n-terminus of the protein. the pgs21a-gp46-i(162-214) was transformed into the chemically competent e. coli bl21 cells and his-gst-gp46-i(162-214) was expressed as an insoluble form. after the isolation of inclusion bodies, his-gst-gp46-i(162-214) was purified and on-column refolding was per- formed using nickel-nitrilotriacetic acid (ni-nta) affinity chromatography. elisa was then applied to assess the antigenicity of the his-gst-gp46-i(162-214) protein using sera specimens from htlv-1 infected patients. results: the sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) results revealed that his-gst-gp46-i(162-214) protein accounted for 30% of the insoluble proteins. the results of elisa highlighted concentration-dependent interactions be- tween the refolded his-gst-gp46-i(162-214) and htlv-1antibodies. furthermore, the refolded his-gst-gp46-i(162-214) and synthetic gp46-i(162-214) had similar reactivity. conclusions: combination of key strategies including codon optimization, expression as inclusion body, and on-column refolding provide an efficient and facile platform for producing gp46-i(162-214) peptide.