Metal Dependent Glycosidases of Sea Cucumber Eupentacta Fraudatrix and their Properties

Sea cucumbers Eupentacta fraudatrix can completely regenerate their organs within one month after evisceration. The regeneration process involves complex structural changes including restructuring of the intracellular matrix. The connective tissue of echinoderms consists of bundles of collagen fibrils and proteoglycans. It is assumed that animals capable of regeneration must possess a diverse set of proteases and glycosylases that modify the connective tissue. Glycosidases catalyze the hydrolysis of glycosidic bonds in carbohydrate molecules, and these enzymes have not yet been studied in the sea cucumber E. fraudatrix. Here four glycosidase-enriched fractions having optimal pH values at 7.0, 7.5 (two fractions), and 6.0 were revealed. Thе glycosidase of Peak 1 (pH 7.0) was moderately activated by Mn²⁺, Ca²⁺, and Zn²⁺ but its best activators are Co²⁺ and Ni²⁺, while Mg²⁺ ions suppress glycosidase activity. Thе glycosidase of Peak 2 (pH 7.5) is activated at low concentrations of Ca²⁺ and Mg²⁺; Mn²⁺ and Co²⁺ increase its activity at higher concentrations, while Ni²⁺ and Zn²⁺ are inhibitors of this enzyme. Thе glycosidase of Peak 3 (pH 7.5) has maximal activity in the presence of Ca²⁺ and Mg²⁺ ions but its activity is suppressed by Mn²+, Ni²⁺, and Zn²⁺. Acid glycosidase (pH 6.0) is Ca²⁺ dependent enzyme, which activity suppresses by several metal ions to varying degrees: Zn²⁺ > Mg²⁺ > Ni²⁺ > Mn²⁺ > Co²⁺. These are the first glycosidases identified in the sea cucumber E. fraudatrix that can be utilized for future studies of their role in extracellular matrix remodeling.