Table 1. DP and composition of selected fractions obtained by SEC of lyase digests of epimerized polyMG.
PolyMG (FG=0.47 and FGG=0.0) was epimerized with AlgE1 and AlgE6 to FG=0.55 for both enzymes. For the AlgE1-epimerized sample, FGG=0.19 and NG>1=7, while for the AlgE6-epimerized sample, FGG=0.17 and NG>1=5. These MG/GG- alginates were degraded by a specific M-lyase from H. tuberculata and separated by SEC on Superdex 30. Fractions with low molecular mass were characterized by ESI-MS, while those with high molecular mass by HPAEC-PAD or MALDI-MS. The composition of fractions were analysed by 1H-NMR (300 MHz) spectroscopy.
| DP | |||
|---|---|---|---|
| SEC fraction | ESI-MS | MALDI-MS/HPAEC-PAD | Composition/sequence 1H-NMR |
| I (AlgE1) | DP52Δ−DP58Δ | FG=0.97 | |
| II (AlgE1) | DP6Δ | ΔGMGMG | |
| III (AlgE1) | DP4Δ | ΔGMG | |
| IV (AlgE1) | DP2Δ | ΔG | |
| I (AlgE6) | DP27Δ−DP35Δ | FG=0.95 | |
| II (AlgE6) | DP13Δ | DP13Δ | FG=0.83 |
| III (AlgE6) | DP4Δ | ΔGMG | |
| IV (AlgE6) | DP2Δ | ΔG | |