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Table 2 Summary of catalytic parameters for the ChiUL enzymes

From: A polysaccharide utilization locus from Flavobacterium johnsoniae enables conversion of recalcitrant chitin

Enzyme Substrate k cat (s−1) K m (mM) k cat /K m (mM−1 s−1)
ChiA_N Chitotriose 0.12 ± 0.007 4.0 ± 0.4 0.031
Chitotetraose 17.4 ± 0.65 0.050 ± 7.3 × 10−3 349
Chitopentaose 20.7 ± 0.93 0.017 ± 3.9 × 10−3 1190
Chitohexaosea 48.8 ± 6.1 0.051 ± 0.012 951
ChiA_C Chitotriose 0.014 ± 6.0 × 10−4 1.17 ± 0.15 0.012
Chitotetraose 0.99 ± 0.03 1.11 ± 0.08 0.89
Chitopentaose 1.66 ± 0.047 0.15 ± 0.02 11.1
Chitohexaose 1.29 ± 0.022 0.071 ± 3.5 × 10−3 18.3
ChiB Chitotriose 0.39 ± 0.014 5.6 ± 0.40 0.069
Chitotetraosea 9.77 ± 1.56 2.2 ± 0.45 4.4
Chitopentaosea 19.9 ± 1.48 0.40 ± 0.052 49.4
Chitohexaosea 60.1 ± 7.4 0.45 ± 0.08 135
GH20 Chitobiose 164 ± 10 0.83 ± 0.13 198
Chitotriose 113 ± 6.8 0.65 ± 0.11 175
Chitotetraose 106 ± 4.1 0.66 ± 0.072 162
Chitopentaose 104 ± 2.8 0.61 ± 0.048 170
Chitohexaose 94.2 ± 4.1 0.51 ± 0.066 183
  1. Values represent means and standard errors from duplicate experiments
  2. Data were fitted to the Michaelis–Menten or substrate inhibition equations (v o  = V max*[S]/(K m + [S] × (1 + [S]/K i )))
  3. aReactions for which substrate inhibition was observed