|
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
|
- Values represent means and standard errors from duplicate experiments
- Data were fitted to the Michaelis–Menten or substrate inhibition equations (v
o
= V
max*[S]/(K
m + [S] × (1 + [S]/K
i
)))
-
aReactions for which substrate inhibition was observed
