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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-2-29
pubmed:abstractText
The glycans linked to the insect cell-derived glycoproteins are known to differ from those expressed mammalian cells, partly because of the low level or lack of glycosyltransferase activities. GnT II, GnT IV, GnT V, and ST3Gal IV, which play important roles in the synthesis of tetraantennary-type complex glycan structures in mammalian cells, were overexpressed in Trichoplusia ni cells by using a baculovirus expression vector. The glycosyltransferases, expressed as a fusion form with the IgG-binding domain, were secreted into the culture media and purified using IgG sepharose resin. The enzyme assay, performed using pyridylaminated-sugar chain as an acceptor, indicated that the purified glycosyltransferases retained their enzyme activities. Human erythropoietin expressed in T. ni cells (rhEPO) was subjected to in vitro glycosylation by using recombinant glycosyltransferases and was converted into complex-type glycan with terminal sialic acid. The presence of N-acetylglucosamine, galactose, and sialic acid on the rhEPO moiety was detected by a lectin blot analysis, and the addition of galactose and sialic acid to rhEPO was confirmed by autoradiography using UDP-14C-Gal and CMP-14C-Sia as donors. The in vitro glycosylated rhEPO was injected into mice, and the number of reticulocytes among the red blood cells was counted using FACS. A significant increase in the number of reticulocytes was not observed in the mice injected with in vitro glycosylated rhEPO as compared with those injected with rhEPO.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1017-7825
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
383-91
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:18309288-Animals, pubmed-meshheading:18309288-Baculoviridae, pubmed-meshheading:18309288-CHO Cells, pubmed-meshheading:18309288-Cell Line, pubmed-meshheading:18309288-Cricetinae, pubmed-meshheading:18309288-Cricetulus, pubmed-meshheading:18309288-Erythropoietin, pubmed-meshheading:18309288-Female, pubmed-meshheading:18309288-Gene Expression, pubmed-meshheading:18309288-Genetic Vectors, pubmed-meshheading:18309288-Glycosylation, pubmed-meshheading:18309288-Humans, pubmed-meshheading:18309288-Mice, pubmed-meshheading:18309288-Moths, pubmed-meshheading:18309288-N-Acetylglucosaminyltransferases, pubmed-meshheading:18309288-Protein Engineering, pubmed-meshheading:18309288-Recombinant Proteins, pubmed-meshheading:18309288-Reticulocytes, pubmed-meshheading:18309288-Sialyltransferases
pubmed:year
2008
pubmed:articleTitle
Expression and characterization of human N-acetylglucosaminyltransferases and alpha2,3-sialyltransferase in insect cells for in vitro glycosylation of recombinant erythropoietin.
pubmed:affiliation
Department of Life Science, Sogang University, Seoul 121-742, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't