title: Effect of modification of carbohydrate component on properties of glucoamylase.
abstract: In this study, we investigated enzymatic deglycosylation of glucoamylase from Aspergillus awamori X 100/D27, a glycoprotein which has two N-linked and about forty short mannose-bearing O-linked sugars per molecule. O-Linked sugars were modified by treatment with alpha-mannosidase and N-linked sugars were removed using endo-beta-N-acetylglucosaminidase F. Analysis of conformational changes following deglycosylation suggests that O-linked sugars essentially contribute to the stabilization of glucoamylase domains. Modification of the carbohydrate component by adding 1-deoxymannojirimycin to the culture medium induced inhibition of alpha-mannosidases involved in the processing, leading to a more complete glycosylation and, consequently, to a higher stability of the enzyme.
authors.affiliation: Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg, Russian Federation.
authors.forename: K N
authors.initials: KN
authors.lastname: Neustroev
authors.forename: A M
authors.initials: AM
authors.lastname: Golubev
authors.forename: L M
authors.initials: LM
authors.lastname: Firsov
authors.forename: F M
authors.initials: FM
authors.lastname: Ibatullin
authors.forename: I I
authors.initials: II
authors.lastname: Protasevich
authors.forename: A A
authors.initials: AA
authors.lastname: Makarov
mesh_terms: D017485:1-Deoxynojirimycin / Q000737:chemistry; D001230:Aspergillus / Q000201:enzymology; D050260:Carbohydrate Metabolism; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D004795:Enzyme Stability; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008361:Mannosidases / Q000737:chemistry; D008969:Molecular Sequence Data; D011487:Protein Conformation; D013816:Thermodynamics; D043323:alpha-Mannosidase
chemical_list: D002241:Carbohydrates; D017485:1-Deoxynojirimycin; D008361:Mannosidases; D043323:alpha-Mannosidase; D005087:Glucan 1,4-alpha-Glucosidase