Abstract: UGT78H2 is a newly discovered glycosyltransferase from blackberry fruit, and the successfully obtained protein is the basis for further functional characterization. We constructed a prokaryotic expression vector and optimized the induction factors(induction temperature, cell and IPTG concentration, and induction duration) using responsive surface methodology(RSM). (1)the constructed pET32a-UGT78H2 plasmid was successfully transformed into the bacteria BL21(DE3)pLysS; (2)By RSM, incubating at 29.5℃ till cell OD₆₀₀=0.51, IPTG was added to the final concentration of 0.4 mmol·L^-1 to incubate for 7.4 hours, and the most quantities of recombinant UGT78H2 was obtained (166.4 μg·mL^-1); (3)Incubation temperature and the length of culture time extremely significant affected the overall quantities of protein, and IPTG concentration and cell OD interactively determined the recombinant protein at significant level; (4)The recombinant protein was 67.9 kDa in molecular weight, existing as inclusion bodies in most fraction, and purified by utilizing Ni-NTA affiliation column system.

Key words: blackberry, UGT78H2, prokaryotic expression, response surface methodology(RSM), recombinant protein