Table 5.
Specific activities and kinetic parameters of the characterized arabinosyl hydrolases on DA and SBA
| Specific activitya | Released soluble sugarsb | ||
|---|---|---|---|
| Enzymes | SBA | DA | |
| MC57GH51 | 2.02 ± 0.11; Km = 117.02, vmax = 52.67 | ND | Arabinose |
| MC60GH51 | 0.06 ± 0.00; Km and vmax: ND | 0.15 ± 0.01; Km and vmax: ND | Arabinose |
| MC60GH43 | NA | 1.65 ± 0.17; Km = 83.05, vmax = 0.82 | Arabinose |
| MC72GH43-1 | NA | NA | NA |
| MC72GH43-2 | 3.81 ± 0.25; Km = 14.98, vmax = 22.77 | 5.21 ± 0.21; Km = 16.61, vmax = 18.27 | AOS, Arabinose |
| MC68GH43-1 | 7.51 ± 0.31; Km = 9.25, vmax = 2.96 | 2.39 ± 0.26; Km = 11.04, vmax = 23.07 | AOS, Arabinose |
| MC68GH43-2 | ND | 1.74 ± 0.02; Km = 37.44, vmax = 14.02 | Arabinose |
Km in g L−1, vmax in µmol min−1 mg−1, Km and vmax were calculated by Microsoft Excel Solver based on enzyme activities at their optimal conditions with different substrate concentrations. ND means not determined due to insufficient activity or lack of detectable activity. NA means no activity
aSpecific activity in µmol min−1 mg−1. The data show the mean values and standard deviations from three experiments
bSoluble sugars released, analyzed by HPAEC-PAD and TLC
SBA sugar beet arabinan, DA debranched arabinan, AOS arabino-oligosaccharides