Table 1 Kinetic Parameters of pNPG Catalysis for GUS Enzymes.

From: Structure, function, and inhibition of drug reactivating human gut microbial β-glucuronidases

Loop Class

GUS

Optimal pH

kcat (s−1)

Km (mM)

kcat/Km (s−1mM−1)

L1

E. coli

7.4

120 ± 10a

0.13 ± 0.01a

920 ± 10a

L1

E. eligens

6.5

120 ± 8

0.223 ± 0.008

540 ± 20

L1

S. agalactiae

6.5

122 ± 3

0.17 ± 0.01

720 ± 30

L1

C. perfringens

6.5

57 ± 2

0.16 ± 0.02

360 ± 40

L1

F. prausnitzii

6.0

58 ± 4

2.2 ± 0.3

27 ± 2

L1

L. rhamnosus

4.5

10.0 ± 0.7

1.5 ± 0.1

6.7 ± 0.3

L1

R. gnavus

6.5

2.8 ± 0.3b

1.4 ± 0.2b

2.0 ± 0.1b

mL1

B. fragilis

5.0

22 ± 2

0.58 ± 0.09

39 ± 4

L2

B. uniformis

5.5

37 ± 2

0.54 ± 0.06

71 ± 6

mL2

P. merdae

5.5

0.088 ± 0.001

2.40 ± 0.07

0.0368 ± 0.0008

mL1,2

B. ovatus

5.0

0.48 ± 0.03b

1.38 ± 0.01b

0.34 ± 0.02b

NL

B. dorei

6.0

7.5 ± 0.4

1.4 ± 0.1

5.2 ± 0.5

  1. Data are presented as the average of 3 biological replicates and errors are standard error of the mean (SEM). kcat is catalytic rate; Km is Michaelis constant; kcat/Km is catalytic efficiency. Crystal structures reported in this study are underlined. aData were previously reported in Wallace et al.17. bData are reported as apparent kcat and Km values.
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