Cell surface display of synthetic phytochelatins using ice nucleation protein for enhanced heavy metal bioaccumulation.
Synthetic phytochelatins (ECs) composed of (Glu-Cys)nGly are protein analogs of phytochelatin that exhibit improved metal-binding capacity over metallothioneins (MTs). Expression of EC20 on the surface of E. coli using the Lpp-OmpA anchor resulted in improved bioaccumulation of cadmium and mercury, providing a new method for treating heavy metal contamination. To further improve the whole-cell accumulation of heavy metals, EC20 was expressed on the surface of Moraxella sp., a bacterium known to survive in contaminated environments, using the truncated ice nucleation protein (INPNC) anchor. Production of EC20 was approximately three-fold higher in Moraxella sp. than E. coli. As a consequence, the mercury-binding capacity of the recombinant Moraxella sp. was increased by more than 10-fold. Owing to the very high level of surface expression, the use of Moraxella sp. and INPNC anchor may prove to be useful for the remediation of other environmental contaminants.
Bae
Weon
W
Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
Mulchandani
Ashok
A
Chen
Wilfred
W
D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D017931:DNA Primers; D004926:Escherichia coli / Q000378:metabolism; D005978:Glutathione; D008667:Metalloproteins / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009016:Moraxella / Q000235:genetics; D054811:Phytochelatins; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D008667:Metalloproteins; D019216:Metals, Heavy; D011994:Recombinant Proteins; C063113:ice nucleation protein; D054811:Phytochelatins; D005978:Glutathione