Glycosylation of bile-salt-stimulated lipase from human milk: comparison of native and recombinant forms.
Bile-salt-stimulated lipase (BSSL) is an enzyme present in human milk. BSSL is important for fat digestion in infants. It contains one site for N-glycosylation and a serine/threonine-rich domain which is highly O-glycosylated. Both N- and O-linked sugar chains were studied on native BSSL from three donors and compared to the glycosylation of recombinant BSSL produced in Chinese hamster ovary or mouse fibroblast (C-127) cell lines. The carbohydrate composition of oligosaccharides was mapped using sugar and methylation analyses, enzyme-linked immunosorbant assay, and different separation techniques. Native BSSL was found to be highly glycosylated (19-26%). It contained a high amount of fucosylated oligosaccharides and expressed both Lewis a and Lewis b blood group antigens. None of the recombinant BSSL forms contained fucose. N-linked structures on native BSSL were identified as mainly mono- and disialylated biantennary complex type structures with or without fucose substitution. High-pH anion-exchange chromatography analysis indicated that the recombinant forms of BSSL contained similar types of N-glycan structures differing mainly in their content of sialic acid and by the absence of fucose residues. Native BSSL contained predominantly large O-linked oligosaccharides. This was in contrast to the recombinant forms of BSSL which contained mainly short type O-glycans with a high content of sialic acid. Interestingly, the estimated number of O-glycans attached to native BSSL was lower than that for the recombinant forms.
Landberg
E
E
Department of Clinical Chemistry, University Hospital, Linköping, Sweden.
Påhlsson
P
P
Krotkiewski
H
H
Strömqvist
M
M
Hansson
L
L
Lundblad
A
A
D000941:Antigens / Q000737:chemistry / Q000276:immunology; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D006868:Hydrolysis; D008049:Lipase / Q000737:chemistry* / Q000276:immunology; D008895:Milk, Human / Q000201:enzymology*; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D009844:Oligosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D002787:Sterol Esterase
D000941:Antigens; D006023:Glycoproteins; D009005:Monosaccharides; D009844:Oligosaccharides; D011134:Polysaccharides; D011994:Recombinant Proteins; C054784:bile salt-stimulated lipase; D002787:Sterol Esterase; D008049:Lipase