Advanced

Multiple alpha-galactosidases from Aspergillus niger: purification, characterization, and substrate specificities

Ademark, Pia; Larsson, M; Tjerneld, Folke LU and Stålbrand, Henrik LU (2001) In Enzyme and Microbial Technology 29(6-7). p.441-448
Abstract
Enzymes with α-galactosidase activity are produced by many organisms, often in multiple forms. Here we compare the biochemical and hydrolytic properties of four major α-galactosidase forms (α-gal I-IV) that were purified from the culture filtrate of Aspergillus niger. α-Gal II, III and IV appear to be isoforms of the same enzyme, and N-terminal amino acid sequence data suggest that they are closely related or identical to A. niger AglB in family 27 of the glycosyl hydrolases. α-Gal I is a completely different enzyme that belongs to family 36. α-Gal I had an isoelectric point of 4.15 and appears to be a tetramer composed of four 94-kDa subunits. α-Gal II, III and IV were dimers with monomeric molecular masses of 64 kDa and isoelectric... (More)
Enzymes with α-galactosidase activity are produced by many organisms, often in multiple forms. Here we compare the biochemical and hydrolytic properties of four major α-galactosidase forms (α-gal I-IV) that were purified from the culture filtrate of Aspergillus niger. α-Gal II, III and IV appear to be isoforms of the same enzyme, and N-terminal amino acid sequence data suggest that they are closely related or identical to A. niger AglB in family 27 of the glycosyl hydrolases. α-Gal I is a completely different enzyme that belongs to family 36. α-Gal I had an isoelectric point of 4.15 and appears to be a tetramer composed of four 94-kDa subunits. α-Gal II, III and IV were dimers with monomeric molecular masses of 64 kDa and isoelectric points of 4.5, 4.7 and 4.8, respectively. α-Gal II-IV were stable when incubated for 17 h at 50°C and pH 2–5, whereas α-gal I was most stable at pH 5–6. All enzymes had maximal catalytic activity at pH 4.5 and 60°C, and hydrolyzed melibiose, raffinose and stachyose. α-Gal II-IV also degraded galactomanno-oligosaccharides and released 66% of the galactose side groups from polymeric locust bean gum galactomannan. α-Gal I released galactose from locust bean gum only in combination with A. niger β-mannosidase. Kinetic experiments showed that α-gal I hydrolyzed p-nitrophenyl-α-Image-galactopyranoside and melibiose more efficiently than α-gal II-IV. The distinct hydrolytic and biochemical properties of α-gal I and α-gal II-IV further signifies the difference between α-galactosidases of family 27 and 36. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Enzyme and Microbial Technology
volume
29
issue
6-7
pages
441 - 448
publisher
Elsevier
external identifiers
  • scopus:0035807420
ISSN
0141-0229
DOI
10.1016/S0141-0229(01)00415-X
language
English
LU publication?
yes
id
f10d98a2-d669-47e0-9c82-e0c7aa69c0af (old id 42303)
date added to LUP
2007-07-17 14:23:41
date last changed
2018-01-07 05:16:46
@article{f10d98a2-d669-47e0-9c82-e0c7aa69c0af,
  abstract     = {Enzymes with α-galactosidase activity are produced by many organisms, often in multiple forms. Here we compare the biochemical and hydrolytic properties of four major α-galactosidase forms (α-gal I-IV) that were purified from the culture filtrate of Aspergillus niger. α-Gal II, III and IV appear to be isoforms of the same enzyme, and N-terminal amino acid sequence data suggest that they are closely related or identical to A. niger AglB in family 27 of the glycosyl hydrolases. α-Gal I is a completely different enzyme that belongs to family 36. α-Gal I had an isoelectric point of 4.15 and appears to be a tetramer composed of four 94-kDa subunits. α-Gal II, III and IV were dimers with monomeric molecular masses of 64 kDa and isoelectric points of 4.5, 4.7 and 4.8, respectively. α-Gal II-IV were stable when incubated for 17 h at 50°C and pH 2–5, whereas α-gal I was most stable at pH 5–6. All enzymes had maximal catalytic activity at pH 4.5 and 60°C, and hydrolyzed melibiose, raffinose and stachyose. α-Gal II-IV also degraded galactomanno-oligosaccharides and released 66% of the galactose side groups from polymeric locust bean gum galactomannan. α-Gal I released galactose from locust bean gum only in combination with A. niger β-mannosidase. Kinetic experiments showed that α-gal I hydrolyzed p-nitrophenyl-α-Image-galactopyranoside and melibiose more efficiently than α-gal II-IV. The distinct hydrolytic and biochemical properties of α-gal I and α-gal II-IV further signifies the difference between α-galactosidases of family 27 and 36.},
  author       = {Ademark, Pia and Larsson, M and Tjerneld, Folke and Stålbrand, Henrik},
  issn         = {0141-0229},
  language     = {eng},
  number       = {6-7},
  pages        = {441--448},
  publisher    = {Elsevier},
  series       = {Enzyme and Microbial Technology},
  title        = {Multiple alpha-galactosidases from Aspergillus niger: purification, characterization, and substrate specificities},
  url          = {http://dx.doi.org/10.1016/S0141-0229(01)00415-X},
  volume       = {29},
  year         = {2001},
}