THE PRODUCTION OF RECOMBINANT DENGUE VIRUS E-PROTEIN USING ESCHERICHIA-COLI AND PICHIA-PASTORIS

The dengue virus envelope protein was expressed as a GST fusion protei n using E. coli and P. pastoris as expression hosts. In E. coli the re combinant E protein is expressed initially as a soluble 81 kDa GST fus ion protein. Treatment of the fusion protein with thrombin released a 55 kDa protein, which is the expected size for correctly processed, no n-glycosylated recombinant E protein. The antiserum from animals immun ised with this recombinant E protein was found to specifically recogni se the dengue virus E protein in virus-infected cells: thus demonstrat ing the immunogenic nature of the recombinant E protein. This expressi on system allowed production of up to 2 mg of purified recombinant E p rotein from a 11 bacterial culture. In contrast, expression of this GS T fusion protein in P. pastoris is associated with extensive proteolyt ic degradation of the recombinant E protein. However, this proteolytic degradation was not observed in the truncated E protein sequences whi ch were expressed. One of these recombinant fusion proteins, GST E401 was secreted into the culture medium at levels of up to 100 mu g/l of growth medium. (C) 1997 Elsevier Science B.V.