PURIFICATION AND CHARACTERIZATION OF EXTRACELLULAR POLY(BETA-D-1,4-MANNURONIDE) LYASE FROM DENDRYPHIELLA-SALINA IFO-32129

An extracellular endo poly(beta-D-1,4-mannuronide) lyase of Dendryphie lla salina IF 32139 was purified to homogeneity by Q Sepharose FF and Sephacryl S-200 HR column chromatographies. The purified enzyme had a molecular weight of 35,000 by sodium dodecyl sulfate-polyacrylamide ge l electrophoresis and an isoelectric point of 3.65 by isoelectric focu sing. The optimum pH and temperature for enzyme activity were pH 5.0 a nd 45 degrees C, respectively. The enzyme was stable from pH 4 to 10 a nd at temperature below 40 degrees C. Some divalent cations, Ca2+, Mn2 +, and Zn2+, increased the enzyme activity. Hg2+ and NBS strongly inhi bited the activity. This enzyme susceptibly degraded poly-M, produced a wide range of 4,5-unsaturated oligomannuronic acids, and further deg raded these unsaturated oligomannuronic acids to produce the unsaturat ed monomer and dimer as final products.