Soluble Expression of Recombinant Human Apoliprotein A-I-Milano in Escherichia coli
重组人载脂蛋白AI米兰突变体在大肠杆菌中的可溶性表达

Apolipoprotein A-I-Milano(AIM),a natural variant, not only inhibits the initiation and progression of atherosclerosis,but also makes the preexisting atherosclerotic lesions regress.AIM gene, at which N-terminal codens were optimized,was subcloned into the expression vector of pET22b.Recombiant plasmids were transformed into E.coli strain BL21(DE3) and induced with IPTG.The expressed apoliprotein A-I-Milano was soluble in E.coli and was about 38% of total cell lysate.Purified by Butyl Sepharose 4F.F hydrophobic chromatography and Q Sepharose H.P. anion exchange chromatography,followed by ultrafiltration with Vivaspin 20(30 000MW),AIM monomer was obtained in a purity of more than 95%. Activity assay of binding of AIM monomer to lipid indicates that association of AIM monomer with DMPC is slower than normal apoA-I but DMPC number associated by AIM monomer is more than by apoA-I.This results will be important for studying structure,function of AIM,specially clinical application.