[Bioinformatics analysis and construction of eukaryotic expression vector of MAGE-D4]

Objective To analyze the physicochemical properties, structure and function of melanoma-associated antigen D4 (MAGE-D4) protein, and then construct the eukaryotic expression vector of MAGE-D4. Methods The physicochemical properties, structure and function of MAGE-D4 protein were analyzed by bioinformatics. Using MAGE-D4/pMAL-C2 prokaryotic recombinant plasmid as the template, PCR product digested by restriction enzyme was connected with pEGFP-C1 eukaryotic expression plasmid and transformed into E. coli. Ligation products were identified by antibiotic screening, enzyme digestion and sequencing. Then the recombinant plasmid was transfected into A549 lung cancer cells by liposome. Results MAGE-D4 protein was an unstable hydrophilic protein without transmembrane structure and signal peptide. Its secondary structure was mainly α-helix. MAGE-D4 contained multiple functional modification sites and was mainly located in the nucleus. SLLLVILGV might be a restricted T cell epitope of HLA-A*0201 derived from MAGE-D4. The first three proteins to potentially interact with MAGE-D4 were NSMCE4A, MLANA/MART-1 and BAGE5. DNA sequencing showed that the recombinant plasmid contained full-length coding sequence (CDS) of MAGE-D4 and it could be successfully transfected into A549 lung cancer cells. Conclusion MAGE-D4 protein is an unstable nuclear protein, which may play functions by interacting with a variety of melanoma-related proteins. The peptide derived from MAGE-D4 may have strong immunogenicity. The eukaryotic expression vector of MAGE-D4 has been successfully constructed.