Substrate | Km
(μM) | kcat
(s
-1
) | kcat
/Km
(M
-1
s
-1
) |
---|
p NP-GlcNAc (Vh Nag1) | 172 ± 48a | 0.08 | 465 |
p NP-GlcNAc(Vh Nag2) | 77 ± 17 | 0.38 | 4,935 |
GlcNAc2 | 179 ± 52 | 0.01 | 56 |
GlcNAc3 | 441 ± 98 | 0.10 | 228 |
GlcNAc4 | 329 ± 93 | 0.10 | 304 |
GlcNAc5 | 496 ± 78 | 0.09 | 181 |
GlcNAc6 | 421 ± 76 | 0.07 | 166 |
- a Results are means ± SD (n = 3 experiments for each substrate).
- The initial velocity of the reaction catalyzed by V. harveyi GlcNAcases was measured at 37°C, 10 min with varied concentrations of chitin oligosaccharides from 0-500 μM. The release of products was determined by the reducing sugar assay (see text). The kinetic experiments were carried out in triplicate. The kinetic parameters (Km, kcat, and kcat/Km) were estimated from a non-linear regression function available in GraphPad Prism v.5.0.