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Table 4 Steady-state kinetic constants for hydrolysis of penicillins by wild-type L1 and L1 mutants.

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

  pencilin G ampicillin
Enzyme Km (μM) kcat (s-1) kcat/Km × 107 Km (μM) kcat (s-1) kcat/Km × 107
w.t. 38 ± 12 600 ± 100 1.6 55 ± 5 520 ± 10 0.95
S224A 70 ± 20 580 ± 100 0.83 125 ± 13 339 ± 1 0.27
S224K 44 ± 8 124 ± 12 0.28 25 ± 3 152 ± 2 0.61
S224D 1600 ± 200 42 ± 9 0.0026 1100 ± 240 10 ± 1 0.00091
I164A 60 ± 5 698 ± 100 1.2 43 ± 3 524 ± 100 1.2
F158A 50 ± 5 138 ± 10 0.28 165 ± 20 270 ± 30 0.16
Y228A 410 ± 60 609 ± 64 0.15 710 ± 74 443 ± 10 0.062
Y228F 140 ± 14 630 ± 30 0.45 271 ± 40 243 ± 30 0.090
N233L 33 ± 9 184 ± 35 0.56 90 ± 20 508 ± 40 0.56
N233D 60 ± 2 440 ± 86 0.73 117 ± 18 621 ± 31 0.53