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Table 5 Steady-state kinetic constants for hydrolysis of carbapenems by wild-type L1 and L1 mutants

From: Probing substrate binding to Metallo-β-Lactamase L1 from Stenotrophomonas maltophilia by using site-directed mutagenesis

  biapenem imipenem meropenem
Enzyme Km (μM) kcat (s-1) kcat/Km × 107 Km (μM) kcat (s-1) kcat/Km × 107 Km (μM) kcat (s-1) kcat/Km × 107
w.t. 32 ± 1 134 ± 4 0.42 57 ± 7 370 ± 5 0.65 15 ± 4 157 ± 9 1.0
S224A 34 ± 5 56 ± 2 0.16 29 ± 4 100 ± 3 0.34 50 ± 10 244 ± 1 0.49
S224K 100 ± 22 43 ± 2 0.043 60 ± 4 14 ± 1 0.023 12 ± 1 212 ± 1 1.8
S224D 64 ± 7 22 ± 1 0.034 42 ± 4 17 ± 1 0.040 132 ± 23 69 ± 7 0.052
I164A 55 ± 3 112 ± 1 0.20 92 ± 11 570 ± 43 0.62 14 ± 1 96 ± 3 0.69
F158A 50 ± 11 70 ± 5 0.14 100 ± 20 370 ± 50 0.37 7 ± 2 36 ± 2 0.51
Y228A 175 ± 25 21 ± 2 0.012 350 ± 94 134 ± 36 0.038 4.5 ± 0.2 26 ± 1 0.58
Y228F 150 ± 23 51 ± 4 0.034 107 ± 13 83 ± 10 0.078 13 ± 1 70 ± 1 0.54
N233L 29 ± 3 105 ± 6 0.36 36 ± 5 250 ± 20 0.69 12 ± 1 67 ± 3 0.56
N233D 28 ± 8 7 ± 1 0.025 71 ± 16 158 ± 13 0.22 16 ± 4 3.5 ± 0.1 0.022