Table 2. Composition and G-lyase degradation patterns of AlgE1- and AlgE6-epimerized mannuronate oligomers.
Molar fractions FG and FGG of the samples after 24 h reaction time were obtained by integration of 1H-NMR spectra (400 MHz). The molecular masses of saturated and unsaturated oligomers in the G-lyase digests of the samples were obtained by ESI-MS. A non-epimerized heptamer of mannuronan was used as a negative control of the specificity of the G-lyase from K. pneumoniae.
| Molar fraction | ||||
|---|---|---|---|---|
| Mannuronate oligomer (DP) | FG | FGG | Number of residues in saturated oligomers after G-lyase digestion (ESI-MS) | Number of residues in unsaturated oligomers after G-lyase digestion (ESI-MS) |
| After AlgE6 epimerization | ||||
| 7 | 0.05 | 0.01 | 4 (3) | Δ3 and Δ4 |
| 8 | 0.06 | 0.01 | 4 (3 and 5) | Δ3 and Δ4 (Δ5) |
| 9 | 0.12 | 0.03 | 4 (3, 5 and 6) | Δ3, Δ4 and Δ5 (Δ6) |
| After AlgE1 epimerization | ||||
| 8 | 0.03 | 0.01 | 4 and 3 | Δ4 (Δ3 and Δ5) |
| Control | ||||
| 7 | 0.00 | 0.00 | 7 | 0 |