Table 1.
Synergistic effects of multiple endoxylanases with Xyl3A and Ara51A
| Endo-xylanase | Xyl3A | Ara51A | Product concn (mM) on substratea: |
|||||
|---|---|---|---|---|---|---|---|---|
| Wheat arabinoxylan |
Oat spelt xylan |
Birchwood xylan |
||||||
| Xylose | Arabinose | Xylose | Arabinose | Xylose | Arabinose | |||
| − | + | − | 3.42 ± 0.71 | ND | 8.83 ± 1.70 | ND | 8.08 ± 0.25 | ND |
| − | − | + | ND | 33.5 ± 7.42 | ND | 4.90 ± 0.39 | ND | ND |
| − | + | + | 40.3 ± 7.50 | 41.5 ± 5.94 | 24.6 ± 2.23 | 6.14 ± 0.08 | 10.3 ± 1.22 | ND |
| Xyn10A | + | + | 152.6 ± 1.31 | 76.8 ± 2.21 | 94.9 ± 3.05 | 13.6 ± 1.13 | 89.6 ± 5.11 | ND |
| Xyn10B | + | + | 137.9 ± 3.00 | 65.6 ± 2.39 | 65.1 ± 0.98 | 10.6 ± 0.54 | 71.1 ± 2.05 | ND |
| Xyn11D | + | + | 128.4 ± 11.56 | 56.2 ± 3.74 | 165.7 ± 7.26 | 21.2 ± 1.01 | 117.5 ± 3.96 | ND |
| Xyn11E | + | + | 114.2 ± 22.07 | 53.2 ± 2.32 | 119.7 ± 1.96 | 17.2 ± 0.30 | 83.3 ± 8.67 | ND |
| Xyn11F | + | + | 109.7 ± 17.11 | 53.4 ± 1.72 | 150.5 ± 5.11 | 19.8 ± 2.53 | 99.3 ± 14.4 | ND |
a
The experiments were performed in triplicates, and data are reported as means ± standard deviation from the mean. Each enzyme, either endoxylanase or accessory protein (Xyl3A or Ara51A), was present at a concentration of 0.5 μM. The enzyme or combination of enzymes was incubated with the xylan substrates (8%, wt/vol) in 50 mM Na-phosphate buffer with 150 mM NaCl (pH 6.5) at 37°C for 15 h. The products were determined by an HPLC method as described in Materials and Methods. ND, concentration was below the detection limit.