@article{95ac2ffb40df49aab126725356fd3427,
title = "Hydrolytic properties of a beta-mannosidase purified from Aspergillus niger. J. Biotechnol. 75: 281-289.",
abstract = "A β-mannosidase was purified to homogeneity from the culture filtrate of Aspergillus niger. A specific activity of 500 nkat mg−1 and a 53-fold purification was achieved using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration. The isolated enzyme has an isoelectric point of 5.0 and appears to be a dimer composed of two 135-kDa subunits. It is a glycoprotein and contains 17% N-linked carbohydrate by weight. Maximal activity was observed at pH 2.4–5.0 and at 70°C. The β-mannosidase hydrolyzed β-1,4-linked manno-oligosaccharides of degree of polymerization (DP) 2–6 and also released mannose from polymeric ivory nut mannan and galactomannan. The Km and Vmax values for p-nitrophenyl-β-Image-mannopyranoside were 0.30 mM and 500 nkat mg−1, respectively. Hydrolysis of Image-galactose substituted manno-oligosaccharides showed that the β-mannosidase was able to cleave up to, but not beyond, a side group. An internal peptide sequence of 15 amino acids was highly similar to that of an Aspergillus aculeatus β-mannosidase belonging to family 2 of glycosyl hydrolases.",
keywords = "Hydrolysis, Manno-oligosaccharides, Aspergillus niger, β-Mannosidase",
author = "Pia Ademark and Jon Lundqvist and Per H{\"a}gglund and M Tenkanen and N Torto and Folke Tjerneld and Henrik St{\aa}lbrand",
note = "The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Analytical Chemistry (S/LTH) (011001004), Biochemistry and Structural Biology (S) (000006142)",
year = "1999",
doi = "10.1016/S0168-1656(99)00172-8",
language = "English",
volume = "75",
pages = "281--289",
journal = "Journal of Biotechnology",
issn = "1873-4863",
publisher = "Elsevier",
number = "2-3",
}