Table 1.

Expression and stability of β-lactamase variants

EpitopeMutationExpressionStability
6M20A0.05ND*
6K21A1.730.53
6S24A2.231.11
6V30A0.127.6
36L107A0.10ND*
36D108A0.09ND*
36T113A0.21ND*
36P118A0.16ND*
49T146A0.470.42
49T147A0.430.38
49L149A0.730.2
49I155A0.19ND*
107S324A0.800.65
107V326A0.530.50
107I329A0.05ND*
107P330A0.06ND*
  • NOTE: Variants were grown in Luria-Bertani medium at 37°C and lactamase expression was measured after 1 day. Thermostability was measured after incubation at 56°C for 1 hour. The parent enzyme β-lactamase retains ∼6% of its activity after heat stress. Expression and stability data are average of two to four replicates and shown relative to the parent enzyme β-lactamase, which was set to 1.

  • * Expression was too low to allow stability assessment.