Monosialylated biantennary N-glycoforms containing GalNAc-GlcNAc antennae predominate when human EPO is expressed in goat milk

Montesino, R.; Toledo, J. R.; Sanchez, O.; Sanchez, A.; Harvey, D. J.; Royle, L.; Dwek, R. A.; Rudd, P. M.; Gerwig, G. J.; Kamerling, J. P.; Cremata, J. A.


Recently, our group reported the expression of recombinant human erythropoietin in goat milk (rhEPO-milk) as well as in the mammary epithelial cell line GMGE (EPO-GMGE) by cell culture using the adenoviral transduction system. N-Glycosylation characterization of rhEPO-milk by Normal-Phase HPLC profiling of the fluorophore, 4-aminobenzoic acid-labeled enzymatically released N-glycan pool from rhEPO-goat milk, combined with MALDI, ESI-MS and LC/MS, revealed that low branched, core-fucosylated, N-glycans predominate. The labeled N-glycans were separated into neutral and charged fractions by anion exchange chromatography and the charged N-glycans were found to be mostly alpha 2,6-monosialylated with Neu5Ac or Neu5Gc in a ratio of 1:1. Unlike the N-glycans from rhEPO produced in CHO cells, where the glycans are multiantennary highly sialylated, core-fucosylated oligosaccahrides, or even in the goat mammary gland epithelial cell line cultured in vitro in which multiantennary, core- and outer-arm fucosylated, monosialylated N-glycans are the most abundant species, a large proportion of the N-glycans from rhEPO-milk were monosialylated, biantennary, antennae mostly terminating with the more unusual GalNAc-GlcNAc motive and without outer-arm fucosylation. These findings, emphasizing the difference in the N-glycan repertoire between the rhEPO-milk and EPO-GMGE, are consistent with the principle that glycosylation is cell-type dependent and that the cell environment is crucial as well. (c) 2007 Elsevier Inc. All rights reserved.

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Título según WOS: ID WOS:000253169500009 Not found in local WOS DB
Volumen: 470
Número: 2
Editorial: Elsevier Science Inc.
Fecha de publicación: 2008
Página de inicio: 163
Página final: 175


Notas: ISI