Enzymatic Conversion of RBCs by [alpha]-N-Acetylgalactosaminidase from Spirosoma linguale

Spirosoma linguale is a free-living nonpathogenic organism. Like many other bacteria, S. linguale produces a cell-associated [alpha]-N-acetylgalactosaminidase. This work was undertaken to elucidate the nature of this activity. The recombinant enzyme was produced, purified, and examined for biochemical attributes. The purified enzyme was ~50 kDa active as a homodimer in solution. It catalyzed hydrolysis of [alpha]-N-acetylgalactosamine at pH 7 Calculated [K.sub.M] was 1.1 mM with [k.sub.cat] of 173 [s.sup.-1]. The described enzyme belongs to the GH109 family.