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. 2021 Sep 17;65(10):e00936-21. doi: 10.1128/AAC.00936-21

TABLE 2.

Kinetic parameters for SIE-1 and representative B3 MBLsi

Substrate SIE-1
 L1
 AIM-1d
 GOB-1e
 CSR-1f
 NDM-1
k cat Km kcat/Km k cat Km kcat/Km k cat Km kcat/Km k cat Km kcat/Km k cat Km kcat/Km k cat Km kcat/Km
Penicillin G 360 ± 20 450 ± 50 790 410 75a 5470 778 31 25,000 630 190 3400 17 250 70 11 16g 680
Ampicillin 100 ± 20 1,900 ± 600 50 580 300a 1930 594 41 14,000 ND ND ND 11 178 60 15 22g 660
Carbenicillin 99 ± 6 250 ± 50 400 ND ND ND ND ND ND ND ND ND 1 210 5 108 285h 380
Meropenem 92 ± 6 100 ± 20 910 77 13c 5,920 1,000 163 6,100 170 22 8,000 6 310 20 12 49g 250
Imipenem 27 ± 3 250 ± 60 110 384 48b 8,000 1,700 97 18,000 85 13 6,500 8 276 30 20 94g 210
Biapenem 1 ± 0.2 150 ± 50 7 64 75a 850 235 290 850 ND ND ND 9 298 30 30 120h 250
Cephalothin 16 ± 1 13 ± 1 1260 65 43a 1510 529 38 14,000 32 7.9 4000 ND ND ND 4 10g 400
Cefuroxime 25 ± 2 25 ± 5 990 53 130a 410 292 29 10,000 ND ND ND 1.0 110 10 5 8g 610
Nitrocefin 29 ± 3 32 ± 5 900 31 12 2,600 240 96 2,500 14 16 870 2 74 30 10 15h 670
a

Data for L1 were reported previously by Crowder et al. (39).

b

Data for L1 were reported previously by Simm et al. (40).

c

Data for L1 were reported previously by Spencer et al. (41).

d

Data for AIM-1 were reported previously by Yong et al. and Selleck et al. (35, 66).

e

Data for GOB-1 were reported previously by Horsfall et al. (13).

f

Data for CSR-1 were reported previously by Pedroso et al. (11).

g

Data for NDM-1 were reported previously by Yong et al. (67).

h

Data for NDM-1 were reported previously by Marcoccia et al. (68).

i

Representative B3 MBLs contain the canonical active site motif (L1 and AIM-1) or the B3-Q (GOB-1) and B3-RQK (CSR-1) variants for the hydrolysis of representative penicillin (penicillin G and ampicillin), cephalosporin (cephalothin, cefuroxime), and carbapenem (meropenem and imipenem) substrates. Units for kcat and Km values and kcat/Km ratio are s−1, μM, and s−1/mM, respectively. Also included are corresponding data for the B1 MBL NDM-1 for comparison. ND, not determined. Data were measured in triplicate, and variation is reported as standard errors.