Selection of the most active enzymes from a mixture of phage-displayed β-lactamase mutants

A mixture of phages displaying the wild type and four mutant Rtem β-lactamases was submitted to three rounds of selection by incubation with a biotinylated suicide inhibitor followed by chromatography on streptavidin coated beads. The final mixture of selected phages was shown to be made up of two third of phages displaying the most active enzyme, present initially as a minor component and 25 percent of a mutant with a five fold lower activity. This technique allows to select for catalytic efficiency. Abstract A mixture of phages displaying the wild type and four mutant Rtem ß-lactamases was submitted to three rounds of selection by incubation with a biotinylated suicide inhibitor followed by chromatography on streptavidin coated beads. The final mixture of selected phages was shown to be made up of two third of phages displaying the most active enzyme, present initially as a minor component, and 25 percent of a mutant with a five fold lower activity. This technique allows to select for catalytic efficiency.