Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Variation in the relative catalytic efficiencies of the mutant β-lactamases relative to WT TEM-1, plotted on a logarithmic scale. The greatest increase in activity was observed toward the extended-spectrum cephalosporin, CTX, used in the selection. Activity toward two first-generation cephalosporins, CF and CZ, increased only slightly relative to TEM-1. However, the important loss of activity toward the native substrate, BZ, was a negative trade-off to the increased CTX activity.
