Hydrolytic properties of a β-mannosidase purified from Aspergillus niger

Characterization of a β-D-mannosidase from a marine gastropod, Aplysia kurodai

“…This result indicated that AkMnsd exolytically cleaved the -1,4-mannosidic bond of mannooligosaccharides. Such an exotype action has been found in the mannosidases from a terrestrial snail, H. pomatia (McCleary, 1983) and A. niger (Ademark et al, 1999) and these enzymes were shown to act on the non-reducing terminus of substrates.…”

“…On the other hand, the optimum pH and temperature of β-mannosidase from a terrestrial mollusk, H. pomatia, were at pH 4.0 and 55 o C (McCleary, 1983). Most of fungal β-mannosidases showed optimal activity in acidic pHs, i.e., pH 2.4-5.0 for A. niger (Ademark et al, 1999) and pH 3.5…”

“…β-Mannosidases from some organisms also showed similar pH stability in acidic conditions. For example, T. reesei enzyme was stable in a pH range of 3.5-6.0 (Kulminskaya et al, 1999) and A. niger enzyme was stable at pH 4.0-6.0 (Ademark et al, 1999). However, thermal stability of AkMnsd in the acidic pH range was somewhat lower compared with β-mannosidases from A. niger (Bouquelet et al, 1978) and Thermotoga neapolitana 5068 (Duffaud et al, 1997 higher Km values i.e., 1.43 mM and 6.5 mM were determined for other molluscan β-mannosidase from H. pomatia (McCleary, 1983) and A. fulica (Sugahara et al, 1972), respectively.…”

Phylogenetic analysis and substrate specificity of GH2 β‐mannosidases from Aspergillus species

“…MndB released mannose from both M 2 and M 3 . Interestingly, MndB released only the terminal non-reducing mannose residue from GM 3 (Fig. 3, lane 6) , whereas, no mannose release was detected from action on GM 2 (Fig.…”

“…The GH2 b-mannosidase MndA from Aspergillus niger is the only cloned b-mannosidase from Aspergilli which has been characterised on natural substrates [3]. The b-mannosidase MndB (AN3368) [16] from Aspergillus nidulans was identified using pNPb-Man screening in a dedicated global shotgun gene expression effort [15].…”