title: Heterogeneous glycosylation of cationic peanut peroxidase.
abstract: Cationic peanut peroxidase (CPrx) from a cell suspension culture is N-glycosylated at Asn60, Asn144, and Asn185. All three N-glycans are complex type and galactose rich, and show heterogeneity in length and ConA (concanavalin A) binding property. The glycan heterogeneity causes a polymorphism of the enzyme. Based on its behavior on ConA columns, CPrx can be grouped into two fractions: nonbinding (CPrx-) and binding (CPrx+) types. A synchronously cosecreted beta-galactosidase has been discovered in the culture medium; there are two isozymes of 60 kDa (pI 7.3) and 66 kDa (pI 7.6). This beta-galactosidase has been partially purified by a combination of ion-exchange and size-exclusion chromatographies and preparative isoelectrofocusing. In vitro experiments indicate that the cosecreted beta-galactosidase is able to convert peroxidase from CPrx- to CPrx+ and may, to some extent, contribute to the glycan heterogeneity of peroxidase in the cell culture.
authors.affiliation: Department of Plant Sciences, University of Western Ontario, London, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Wan
authors.forename: M
authors.initials: M
authors.lastname: Gijzen
authors.forename: R B
authors.initials: RB
authors.lastname: Van Huystee
mesh_terms: D010367:Arachis / Q000201:enzymology*; D001216:Asparagine / Q000378:metabolism*; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003208:Concanavalin A / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D037121:Plant Lectins; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D001616:beta-Galactosidase / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D037121:Plant Lectins; D011134:Polysaccharides; D003208:Concanavalin A; D001216:Asparagine; D010544:Peroxidases; D001616:beta-Galactosidase