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Abstract

The efficiency of secretion of Escherichia coli alkaline phosphatase depends on the presence in cells of a cytoplasmic chaperone--protein SecB. Secretion increases in the presence of this chaperone at 30 degrees C, which is the most favorable for the interaction of SecB with the export-initiation domain found previously in the N-terminal region of the mature enzyme. This interaction most likely occurs in the region of the export domain, which is located close to the signal peptide and in complex with a translocational ATPase--protein SecA.

Extracellular expression ofAerococcus viridanspyruvate oxidase in recombinantEscherichia colithrough SecB co-expression

“… 25 The high yield of extracellular POD obtained at 25 °C with a relatively low cell density suggested that SecB had a positive effect on POD peptide. 17 To further increase the extracellular POD yield, glycine was added to release the POD within the cell, although glycine inhibited cell growth owing to cell leakage. The high yield of extracellular POD demonstrated the effect of glycine on protein leakage.…”

“…In a previous study, Kononova achieved a twofold increase in phoA secretion by increasing the concentration of SecB. 17 Similarly, Zhou obtained 50% increase in human lymphotoxin expression in E. coli by co-expressing SecB. 18 However, excessive chaperone expression could be a burden to the E. coli cells, leading to an increase in the formation of inclusion bodies.…”