[Expression and purification of epitope peptide of human tyrosinase and its antigenicity in vitiligo patients].

OBJECTIVE

To express the epitope peptide of human tyrosinase (TYR), and discuss the application of the peptide in detecting autoantibody of the vitiligo patients.

METHODS

The epitope areas 240 - 255, 289 - 294, 295 - 300, 435 - 447, and 461 - 479 of human TYR were synthesized and connected to the vector pGEM-T. The target gene was cloned to the prokaryotic expression vector pGEX-4T-2, which was then transferred to Escherichia coli BL21 host cells. Isopropy-beta-D-thiogalactoside (IPTG) was used to induce the protein expression that was examined with SDS-PAGE and Western blotting. Indirect ELISA was conducted to detect the antigenicity of the peptide in 100 blood specimens of active vitiligo patients and 30 healthy controls.

RESULTS

The recombinant expression vector was constructed successfully. The SDS-PAGE and Western blotting results showed expression of the recombinant protein in E. coli. The amount of the recombinant protein reached about 70% of the total mass of bacterial protein with PAGE analysis system. With the glutathione S-transferase (GST) purification kit, the purity of recombinant protein reached over 90%. Indirect ELISA showed that reaction with the target protein was negative in all the 30 healthy controls and was positive in 64 of the 100 active vitiligo patients.

CONCLUSION

The epitope peptide of human TRY is expressed successfully, and it has antigenicity in the serum of vitiligo patients.