Degradation of algal (Ascophyllum nodosum) fucoidan by an enzymatic activity contained in digestive glands of the marine mollusc Pecten maximus

A protein extract from digestive glands of the marine mollusc Pecten maximus was shown to possess fucoidan-degrading activity. This activity was able to release l-fucose from fucoidan derived from the brown algae Ascophyllum nodosum, and markedly reduce the molecular size of the polysaccharide. An enzymatically degraded fucoidan was produced and analysed by NMR spectroscopy. The 2D 1H NMR data obtained for the first time on low-molecular-weight fractions of algal fucoidan provided new insight into the structure of the polysaccharide. The latter has a randomly organised structure, involving (1→3)- and (1→4)-linked unsulfated and 2-sulfated-α-l-fucose residues.