title: A novel strategy for enhancing extracellular secretion of recombinant proteins in Escherichia coli.
abstract: Secretion of cytoplasmic expressed proteins into culture medium has significant commercial advantages in large-scale production of proteins. Our previous study demonstrated that the membrane permeability of Escherichia coli could be significantly improved when Thermobifida fusca cutinase, without a signal peptide, was expressed in cytoplasm. This study investigated the extracellular production of other recombinant proteins, including both secretory and cytosolic proteins, with co-expression of cutinase. When the secretory enzymes, xylanase and α-amylase, were co-expressed with cutinase, the culture period was shortened by half, and the productivity was 7.9 and 2.0-fold to that of their individual control without co-expression, respectively. When the normally cytosolic proteins, xylose isomerase and trehalose synthase, were co-expressed with cutinase, more than half of the target proteins were "secreted" into the culture medium. Moreover, by using β-galactosidase to detect membrane leakage, the improved secretion of the above model proteins was confirmed not to be due to cell lysis. The study provides a novel strategy for enhancing extracellular secretion of recombinant proteins in E. coli.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Ave, Wuxi, Jiangsu, 214122, China.
authors.forename: Lingqia
authors.initials: L
authors.lastname: Su
authors.forename: Chenhua
authors.initials: C
authors.lastname: Xu
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Woodard
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
mesh_terms: D001483:Base Sequence; D018533:Biomass; D003001:Cloning, Molecular; D003470:Culture Media; D003600:Cytosol / Q000201:enzymology; D017931:DNA Primers; D004926:Escherichia coli / Q000378:metabolism*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D007535:Isomerases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D000516:alpha-Amylases / Q000235:genetics / Q000378:metabolism
chemical_list: D003470:Culture Media; D017931:DNA Primers; D011994:Recombinant Proteins; D005964:Glucosyltransferases; C099692:trehalose synthase; D000516:alpha-Amylases; D007535:Isomerases