Table 2. Kinetic parameters of some chitinases.
| Sources and names of chitinases | Substrate | Km | kcat | Vmax | kcat /Km | Reference |
|---|---|---|---|---|---|---|
| Serratia marcescens | ||||||
| ChiA | 4-MU-(GlcNAc)2 | [S]0.5 = 135 µM | 104 s−1 | – | – | [69] |
| 4-MU-(GlcNAc)3 | 4.29 ± 0.4 µM | 67 ± 3 s−1 | – | – | [68] | |
| ChiB | 4-MU-(GlcNAc)2 | 34.1 ± 1.4 µM | 19.1 ± 0.7 s−1 | – | – | [69] |
| 4-MU-(GlcNAc)3 | 6.8 ± 1.0 µM | 57 ± 4 s−1 | – | – | [68] | |
| ChiC | 4-MU-(GlcNAc)3 | 80 ± 8 µM | 2.0 ± 0.1 s−1 | – | – | [68] |
| Barley chitinase | 4-MU-(GlcNAc)3 | 33 µM | 0.36 min−1 | 12 µmol min−1mg−1 | 1.7 × 102 M−1 s−1 | [125] |
| (GlcNAc)4 | 3 µM | 35 min−1 | 1.2 µmol min−1mg−1 | 1.9 × 105 M−1 s−1 | [125] | |
| Vibrio harveyi ChiA | (GlcNAc)5 | 380 ± 49 µM | 0.2 s−1 | – | 5.5 × 10−4 s−1 µM−1 | [92] |
| (GlcNAc)6 | 174 ± 23 µM | 0.19 s−1 | – | 11 × 10−4 s−1 µM−1 | [92] | |
| CC | 12 ± 1.4 mg ml−1 | 0.10 s−1 | – | 83 × 10−4 s−1 mg−1 ml−1 | [92] | |
| Trichoderma atroviride Ech30 | 4-MU-[GlcNAc)2 | 149 ± 29 µM | 0.0048 ± 0.0004 s−1 | – | [93] | |
| Serratia proteamaculans SpChiD | Colloidal | 83 mg ml−1 | 3.9 × 102 h−1 | –- | 4.7 h−1mg−1 ml−1 | [24] |
| (GlcNAc)2 | 203 µM | 1.3 × 102 h−1 | – | 0.62 h−1 µM−1 | [24] | |
| Bacillus licheniformis ChiA-65 | p-NP-(GlcNAc)2 | 0.646 mg ml−1 | 24501 s−1 | 36752 U mg−1 | 37927 ± 9.45 | [26] |
| CC | 0.385 mg ml−1 | 5000 s−1 | 7500 U mg−1 | 12987 ± 6.45 | [26] | |
| Bacillus thuringiensis BthChi74 | 4-MU-(GlcNAc)2 | 159 ± 0.5 µM | 1.5 ± 0.02 s−1 | – | 0.01 s−1µM−1 | [126] |
| Bacillus circulans Bc ChiA1 | p-NP-(GlcNAc)2 | 2.2 ± 0.5 mM | 378 ± 65 min−1 | – | – | [112] |
| Streptomyces coelicolor ScChiC | Crab shell chitin | 0.4 mg ml−1 | – | 1207 U mg−1 | – | [113] |
| Enterobacter cloacae EcCh1 | CC | 15.2 mg ml−1 | 0.16 × 102 min−1 | 0.011 × 102 mg−1ml min−1 | [84] | |
| Chitobiase | 213.2 μM | 1.41 min−1 | 0.6 × 10−2 min−1 µM−1 | [84] | ||
| Nepenthes alata NaCHIT1 | (GlcNAc)4 | 1.0 mM | 6.8 s−1 | 6.8 s−1 mM−1 | [127] | |
| [GlcNAc]5 | 2.5 mM | 57.2 s−1 | 22.9 s−1 mM−1 | |||
| [GlcNAc]6 | 2.1 mM | 80.7 s−1 | 38.4 s−1 mM−1 |
Abbreviation: p-NP, p-nitrophenyl.