title: Two components of cell-bound isopullulanase from Aspergillus niger ATCC 9642--their purification and enzymatic properties.
abstract: Cell-bound isopullulanase (pullulan 4-glucanohydrolase: EC 3.2.1.57, IPU) from Aspergillus niger ATCC9642 [Y. Sakano et al., Denpun Kagaku, 37, 39-41 (1990)] was separated into two active components, IPU F1 (pI = 5.0) and IPU F2 (pI = 4.9), using a Mono-P HR 5/20 column. The substrate specificity on pullulan and panose, specific activity, optimum pH, pH stability, and susceptibility to certain chemical reagents were similar between IPU F1 and IPU F2. IPU F1 and F2 had an identical N-terminal amino acid sequence, A-V-T-A-D-N-S-Q-L-L. However, IPU F1 contained more total carbohydrate (15.3%) than IPU F2 (12.4%). SDS-polyacrylamide gel electrophoresis showed that the molecular weight of IPU F1 (71,000) was greater than that of IPU F2 (69,000). After deglycosylation of IPU F1 and F2 with peptide-N-glycosidase F, the molecular weights of IPU F1 and F2 became 59,000.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Aoki
authors.lastname: Yopi
authors.forename: A
authors.initials: A
authors.lastname: Padmajanti
authors.forename: Y
authors.initials: Y
authors.lastname: Sakano
mesh_terms: D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000201:enzymology*; D002241:Carbohydrates / Q000032:analysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D008320:Maltose / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002241:Carbohydrates; D005656:Fungal Proteins; D007527:Isoenzymes; D008320:Maltose; D006026:Glycoside Hydrolases; C100181:pullulanase