Characterization of N-glycans from mouse brain neural cell adhesion molecule

Citation
S. Liedtke et al., Characterization of N-glycans from mouse brain neural cell adhesion molecule, GLYCOBIOLOG, 11(5), 2001, pp. 373-384
Citations number
68
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
GLYCOBIOLOGY
ISSN journal
0959-6658 → ACNP
Volume
11
Issue
5
Year of publication
2001
Pages
373 - 384
Database
ISI
SICI code
0959-6658(200105)11:5<373:CONFMB>2.0.ZU;2-T
Abstract
The N-glycosylation pattern of the neural cell adhesion molecule (NCAM), is olated from brains of newborn mice, has been analyzed. Following digestion with trypsin, generated glycopeptides were fractionated by serial immunoaff inity chromatography using immobilized monoclonal antibodies specifically r ecognizing polysialic acid (PSA) units or the HNK1-carbohydrate epitope, Su bsequent analyses of the resulting (glyco)peptides by Edman degradation and matrix-assisted laser desorption/ionization time-of-flight mass spectromet ry (MALDI-TOF-MS) revealed polysialylated glycans to be exclusively linked to glycosylation sites 5 (Asn(431)) and 6 (Asn(460)), whereas glycans carry ing the HNK1-epitope could be assigned to sites 2 (Asn(297)), 5, 6, and, to a lesser extent, site 3 (Asn(329)). PSA-, HNK1-, and non-PSA/HNK1-glycan f ractions were characterized by carbohydrate constituent and methylation ana lyses as well as MALDI-TOF-MS in conjunction with chromatographic fractiona tion techniques. The results revealed that the core structures of PSA-glyca ns represented predominantly fucosylated, partially sulfated 2,6-branched i somers of triantennary as well as tetraantennary complex-type glycans, wher eas carbohydrate chains bearing the HNK1-epitope were dominated by diantenn ary species carrying in part bisecting GlcNAc residues. Non-PSA/HNK1-glycan s exhibited a highly heterogeneous pattern of partially truncated, mostly d iantennary structures being characterized by the presence of additional fuc ose, bisecting GlcNAc and/or sulfate residues. In conclusion, our results r evealed that the glycosylation pattern of murine NCAM displays high structu ral and regional selectivity, which might play an important role in control ling the biological activities of this molecule.