Alginic acid degradation by eliminases from abalone hepatopancreas.

Two separate alginic acid eliminases have been purified from abalone hepatopancreas. Alginase I appeared to be specific for p-1,4 bonds involving o-mannuronic acid units and apparently acts at random on internal bonds. Alginase II appeared to cleave 1,4 bonds involving L-guluronic acid and to work at or near chain ends. A combination of both enzymes could not degrade alginic acid completely, indicating the presence of other types of bonds. An ionic concentration of about 50 to 75 mM was required for maximum activity. It appears that the high ionic strength was necessary to remove bound water from the substrate, alginic acid, and to neutralize the negative charges on the polyanion in order to render the molecular configuration more suitable for enzyme action.