DEXTRAN SUCRASE

Dextran sucrase from Leuconostoc mesenteroides has been used in a study to investigate the functional and structural characterization of α-(1→2) branching sucrase derived from DSR-E glucansucrase. Dextran sucrase from Leuconostoc mesenteroides has also been used in a study to investigate the bioengineering of Leuconostoc mesenteroides glucansucrases.

Dextran Sucrase from Leuconostoc mesenteroides belongs to glycoside hydrolase family 70 (GH70). It functions through a retaining mechanism and uses two catalytic acidic residues. Dextran sucrase has a dextran binding site in the C-terminal domain.

Dextransucrases are glucansucrases that are able to produce dextran, a glucose polymer linked mainly through α1-6 bonds. However, α1-3, α1-6, α1-4 and α1-2 bonds are also found, in both the main chain and the branching linkages. The peptide has approximately 1600 amino acids. The aspartic acid in position 551 is essential for catalytic activity, while glutamic acid 589 and aspartic acid 662 complement the catalytic triad. The activity of dextransucrase is decreased by EDTA, and is restored by the addition of calcium ions. Zinc, cadmium, lead, mercury and copper ions are inhibitory to various degrees.