Abstract
When brain-derived neurotrophic factor (BDNF) is produced in the Escherichia coli periplasm, insoluble BDNF proteins with low biological activity and having mismatched disulfide linkages are formed. The coexpression of cysteine oxidoreductases (DsbA and DsbC) and membrane-bound enzymes (DsbB and DsbD), which play an important role in the formation of disulfide bonds in the periplasm, was investigated to improve the production of soluble and biologically active BDNF. The expression levels of Dsb proteins changed when the growth medium and the Dsb expression plasmids were changed, and the production rate of soluble BDNF was almost proportional to the expression level of DsbC protein with disulfide isomerase activity in the case of a low expression level of BDNF. The rate of soluble BDNF production with coexpression of DsbABCD was as high as 35%. These results show that coexpression of BDNF and Dsb proteins can effectively increase the production of soluble and biologically active BDNF.
