title: [Soluble expression and purification of human alpha-defensin-5 in Escherichia coli].
abstract: DNA fragment containing human alpha-defensin 5 mature peptide (mHD-5) coding sequence with biased codons of E. coli was amplified by PCR, which was subsequently cloned into the plasmid pMAL-p2x in order to create pMAL-p2x-mHD-5 expression vector. The plasmid pMAL-p2x-mHD-5 was transferred into engineered strain BL21(DE3) to express heterogeneous fusion protein (MBP-mHD-5). The soluble MBP-mHD-5 targeted protein inducible expressed by IPTG was accounted for about 30% under optimized conditions. The recombinant mHD-5 (rmHD-5) peptide was successfully purified through a separation process including affinity chromatography, Factor Xa digestion and ion exchange chromatography. The bioactivity of rmHD-5 was examined by bacteria-inhibition tests in liquid culture. The growth of E. coli ATCC25922 was dramatically suppressed with an inhibition rate of 90%, with the presence of 62.5 microg/mL rmHD-5 in the media. These results indicate that the strategy of soluble expression of fusion protein in E. coli can be a useful and practical way to produce bioactive defensins.
authors.affiliation: Institute of Combined Injury of the People's Liberation of Army, National Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chonqqing 400038, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Wang
authors.forename: Yongping
authors.initials: Y
authors.lastname: Su
authors.forename: Tianmin
authors.initials: T
authors.lastname: Cheng
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Zou
authors.forename: Junping
authors.initials: J
authors.lastname: Wang
mesh_terms: D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D012995:Solubility; D014169:Transformation, Bacterial; D023084:alpha-Defensins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C500225:DEFA5 protein, human; D011993:Recombinant Fusion Proteins; D023084:alpha-Defensins