Structural analysis of the degradation products of porphyran digested by Zobellia galactanivorans β-porphyranase A

Porphyran from the red seaweed Porphyra umbilicalis was degraded with β-porphyranase A derived from the marine flavobacterium Zobellia galactanivorans. β-Porphyranase A produces a new series of sulfated oligosaccharides that we characterized by NMR, HPAEC and size-exclusion chromatography. In contrast to previously used β-agarases, which produce predominantly non-sulfated oligosaccharides of the neoagarobiose series and hybrid oligosaccharides, β-porphyranase A produced oligosaccharides of the α-l-Galp-6-sulfate (1 → 3) ß-d-Galp (L6S-G) series and the L6S-G disaccharide was the major final product. The newly identified β-porphyranase A was further used in combination with β-agarase B to revise porphyran polysaccharide structure.