Purification and characterization of beta n acetyl hexosaminidase ec 188.8.131.52 from pycnoporus cinnabarinus
Ohtakara, A.; Yoshida, M.; Murakami, M.; Izumi, T.
Agricultural and Biological Chemistry 45(1): 239-248
ISSN/ISBN: 0002-1369 Accession: 006226417
.beta.-N-Acetylhexosaminidase [.beta.-NAcase] (EC 184.108.40.206) was purified from the culture filtrate of P. cinnabarinus to homogeneity by polyacrylamide disc gel electrophoresis. The ratio of .beta.-GlcNAcase activity to .beta.-GalNAcase activity remained constant during the purification process. The MW of this enzyme was estimated to be .apprx. 120,000 by gel filtration, and the isoelectric point was at about pH 5.4. The optimum pH was at 2.2 for pNPGlcNAc and around 3.7 for pNPGalNAc. The enzyme was relatively stable at acid pH range of 2-4 (for 45 h at 5.degree. C) and below 45.degree. C (for 10 min at pH 2.8). The enzyme hydrolysed chito-oligosaccharides, such as N,N-diacetylchitobiose, N,N,N-triacetylchitotriose and N,N,N,N-tetraacetylchitotetraose.