Enhanced Bioaccumulation of Heavy Metal Ions by Bacterial Cells Due to Surface Display of Short Metal Binding Peptides

AUTOR(ES)

Kotrba, Pavel

FONTE

American Society for Microbiology

RESUMO

Metal binding peptides of sequences Gly-His-His-Pro-His-Gly (named HP) and Gly-Cys-Gly-Cys-Pro-Cys-Gly-Cys-Gly (named CP) were genetically engineered into LamB protein and expressed in Escherichia coli. The Cd2+-to-HP and Cd2+-to-CP stoichiometries of peptides were 1:1 and 3:1, respectively. Hybrid LamB proteins were found to be properly folded in the outer membrane of E. coli. Isolated cell envelopes of E. coli bearing newly added metal binding peptides showed an up to 1.8-fold increase in Cd2+ binding capacity. The bioaccumulation of Cd2+, Cu2+, and Zn2+ by E. coli was evaluated. Surface display of CP multiplied the ability of E. coli to bind Cd2+ from growth medium fourfold. Display of HP peptide did not contribute to an increase in the accumulation of Cu2+ and Zn2+. However, Cu2+ ceased contribution of HP for Cd2+ accumulation, probably due to the strong binding of Cu2+ to HP. Thus, considering the cooperation of cell structures with inserted peptides, the relative affinities of metal binding peptide and, for example, the cell wall to metal ion should be taken into account in the rational design of peptide sequences possessing specificity for a particular metal.

Documentos Relacionados

• Staphylococcal Surface Display of Metal-Binding Polyhistidyl Peptides
• Phytochelatins, a class of heavy-metal-binding peptides from plants, are functionally analogous to metallothioneins
• Generation of Metal-Binding Staphylococci through Surface Display of Combinatorially Engineered Cellulose-Binding Domains
• Development of Bacterium-Based Heavy Metal Biosorbents: Enhanced Uptake of Cadmium and Mercury by Escherichia coli Expressing a Metal Binding Motif
• Enhanced Mercury Biosorption by Bacterial Cells with Surface-Displayed MerR