Fucoidanases.

In recent years, the research of fucoidans has steadily increased. The interest in these substances is due to their various biological activities. Despite a wide range of biological activity and the lack of oral toxicity, fucoidans remain relatively unexploited as a source of medicines because of their heterogeneity. Enzymes that degrade polyanionic polysaccharides are widely used for establishing their structures and structure-activity relationships. Sometimes, to obtain preparations of polysaccharides with standard characteristics, for example, medicines and food supplements, enzymatic treatment can be also applied. Only a few sources of enzymes with fucoidanase activity have been described, and only a few studies regarding the isolation and characterization of fucoidanases have been performed. The data on the specificity of fucoidanases: the type of cleaved glycoside bond, the relation between catalytic activity and the degree of substrate sulfation are scarce. The review summarizes achievements in the research of fucoidanases, mechanisms of enzymatic degradation of fucoidans, as well as of structures of sulfated fucooligosaccharides obtained under the action of fucoidanases.