Hydrolysis of the glycosidic linkage between oligosaccharides and ceramides of glycosphingolipids, optimal substrates appear to be the glycosphingolipids with a gangliotetraose structure. an oligoglycosyl-(1->4)-beta-D-glucosyl-(1<->1)-ceramide + H2O = an N-acyl-sphingoid base + an oligoglycosyl-(1->4)-D-glucose Cu(2+), zinc, manganese, calcium, magnesium and EDTA have no significant effects on enzyme activity. Enzyme requires presence of detergents such as Triton X-100 and Lubrol PX for the hydrolysis of glycosphingolipids. Taurodeoxycholate strongly inhibits the enzyme activity. Optimum pH is 3.0-4.0. Highly stable at acidic pH. Released from digestive cells into the gastric cavity, and eventually into the surrounding medium, during the digestive process. Expressed uniformly in digestive cells, tentacles and peduncle regions suggesting expression in the endoderm throughout the whole body (at protein level). Belongs to the glycosyl hydrolase 5 (cellulase A) family.