Novel beta-D-galactofuranose-containing high-mannose type oligosaccharides in ascorbate oxidase from Acremonium sp. HI-25.
Ascorbate oxidase from the fungus Acremonium sp. HI-25 is a copper-containing glycoprotein that catalyzes the oxidation of ascorbic acid to dehydroascorbic acid. Monosaccharide composition analysis showed that the enzyme contains exclusively N-linked oligosaccharide chains. Following liberation by hydrazinolysis/re-N-acetylation, and fractionation by HPLC on anion exchange. Amide-80 and/or octadecyl silica columns after derivatization with p-aminobenzoic ethyl ester, the structures of the twelve major neutral oligosaccharides were identified by FAB-MS, 400 MHz 1H-NMR, methylation analysis, mild acid hydrolysis, and/or sequential exoglycosidase digestions. Acremonium sp. ascorbate oxidase was found to consist of high-mannose type oligosaccharides (76.3%) having 4 to 9 mannose residues and a series of novel D-galactofuranose-containing high-mannose type oligosaccharides (18.6%) with the following structure.
Ohta
M
M
Department of Biotechnology, Faculty of Engineering, Fukuyama University, Hiroshima, Japan.
Emi
S
S
Iwamoto
H
H
Hirose
J
J
Hiromi
K
K
Itoh
H
H
Shin
T
T
Murao
S
S
Matsuura
F
F
D000164:Acremonium / Q000201:enzymology* / Q000378:metabolism; D001204:Ascorbate Oxidase / Q000737:chemistry / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005690:Galactose / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D016339:Spectrometry, Mass, Fast Atom Bombardment
D009844:Oligosaccharides; D001204:Ascorbate Oxidase; D008358:Mannose; D005690:Galactose