COMPARISON OF CHARACTERISTICS OF BETA-N-ACETYLHEXOSAMINIDASE FROM MOON-JELLYFISH AURELIA-AURITA WITH THOSE FROM OTHER SPECIES

beta-N-Acetylhexosaminidase (EC 3.2.1.52) in moon jellyfish mesogloea was extracted with 50 mM sodium phosphate buffer (pH 6.0) and purified by chromatographies On CM-Toyopearl 650M and Toyopearl HW-55F. By the se two purification steps, the enzyme was isolated from crude extracts . A final specific activity of 17875 units/mg and 19-fold purification were attained. The molecular weight of the enzyme was estimated to be about 130,000 by gel filtration on Toyopearl HW-55F. By SDS-PAGE, the enzyme was composed of a subunit molecular mass of 64,000. The optimu m pH was 4 and the enzyme was stable at the range between 4 and 5. Thi s enzyme was extremely unstable in comparison with those from other sp ecies. The optimum temperature was 50 degrees C. The enzyme was strong ly inhibited by Hg2+, CH2ICOOH, and DTNB, but was slightly activated b y K+, Na+, Mg2+, Cu2+ and Ca2+. The enzyme hydrolyzed various oligosac charides, and the rate of hydrolysis of N-acetylchitooligosaccharides tended to decrease with increasing degree of polymerization of the sub strate. Moreover, in comparison with some other species, this enzyme h ad a high affinity for phenyl-2-acetamide-2-deoxy-beta-D-glucopyranosi de.