Table 1

Kinetic parameters for the hydrolysis of p-NP-Neu5Ac by the pneumococcal sialidases computed using the direct and the indirect spectrophotometric assays (see Materials and Methods for details)
p-NP-Neu5Ac direct method p-NP-Neu5Ac indirect method
kcat(s-1) Km(μM) kcat/Km(M-1·s-1) kcat(s-1) Km(μM) kcat/Km(M-1·s-1)
NanA* >175 >500 (3.5 ± 0.3) × 105 >490 >1,100 (8.4 ± 0.9) × 104
NanB* >0.14 >500 (2.7 ± 0.3) × 102 >11 >1,200 (1.1 ± 0.1) × 102
NanC* >17 >500 (3.4 ± 0.3) × 104 >11 >700 (1.2 ± 0.1) × 104

* first order reaction kinetics were observed with this substrate at concentrations up to 500 μM (direct method) or 1,200 μM (indirect method) and thus only allowed to compute the kcat/Km values.

Hayre et al.

Hayre et al. BMC Biochemistry 2012 13:19   doi:10.1186/1471-2091-13-19

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