Expression of human metallothionein III and its metalloabsorption capability in Escherichia coli.
Human metallothionein III (MT III) gene was synthesized with Escherichia coli preference codon usage and expressed in E. coli in glutathione-S-transferase (GST) fusion form. The recombinant MT III was released by proteinase Factor Xa digestion and purified with the yield of 2 mg/L culture, and its specific Cd2+ binding capability was confirmed. E. coli strain BL21(DE3), expressing MT III, showed metal tolerance between 0.1 and 0.5 mM Cd2+ and bacterial growth was inhibited at 1 mM Cd2+. MT III expressing E. coli strain showed binding discrimination between different metal ions in combination use, with the preference order of Cd2+ > Cu2+ > Zn2+. It absorbed different metal ions with relatively constant ratio and showed a cumulative absorption capability for mixed heavy metals.
State Key Laboratory of Pharmaceutical Biotechnology, State Key Laboratory of Pollution Control and Resource Reuse, Institute of Molecular and Cell Biology, Department of Biochemistry, College of Life Sciences, Nanjing University, Nanjing, P.R. China.
Wei-Juan
WJ
Zheng
Fang
F
Wu
Hong-Qin
HQ
Zhuang
Chun
C
Lu
Feng
F
Yang
Wen-Li
WL
Ma
Zi-Chun
ZC
Hua
D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008668:Metallothionein / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D019216:Metals, Heavy / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
D019216:Metals, Heavy; D011993:Recombinant Fusion Proteins; D008668:Metallothionein