Structures of the asparagine-linked sugar chains of laminin.

Abstract

This investigation describes the isolation and characterization of oligosaccharides of the basement membrane glycoprotein, laminin. Pronase-released glycopeptides of isolated laminin, from a mouse Engelbreth-Holm-Swarm tumor, were fractionated using a combination of gel permeation chromatography and Con A-Sepharose affinity chromatography. The glycopeptides were analyzed for sugar linkage patterns by methylation analysis. Glycopeptides and hydrazine-released oligosaccharides were further analyzed using endo-beta-galactosidase, endo-beta-N-acetylglucosaminidase H and specific exoglycosidases in conjunction with calibrated gel permeation chromatography. Based on these experiments, murine tumor laminin was shown to contain asparagine-linked oligosaccharides with the following structures: bi-, tri- and tetraantennary complex-type oligosaccharides; polylactosaminyl side chains containing Gal(beta 1----4)GlcNAc(beta 1----3) repeating units attached to the trimannose core portion of the bi-, tri- and tetraantennary complex-type oligosaccharides; unusual complex-type oligosaccharides terminated at the nonreducing end with sialic acid, alpha-galactose, beta-galactose and beta-N-acetylglucosamine; alpha-galactosyl residues linked to N-acetyllactosamine sequences; high-mannose-type oligosaccharides. These results, in conjunction with analytical data, indicate that most of the carbohydrate of this laminin is N-linked to asparagine and that there are about 43 such N-linked oligosaccharides per laminin molecule.

• Authors: R G Arumugham, T C Hsieh, M L Tanzer, R A Laine
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 883 Issue 1 Pg. 112-26 (Aug 06 1986) ISSN: 0006-3002 [Print] Netherlands
• PMID: 3730425 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Glycopeptides
• Laminin
• Oligosaccharides
• Asparagine
• Glucosamine
• Galactose

Topics

• Animals
• Asparagine
• Basement Membrane (analysis)
• Carbohydrate Conformation
• Chromatography, Affinity
• Chromatography, Gel
• Galactose (analysis)
• Glucosamine (analysis)
• Glycopeptides (analysis)
• Laminin (analysis)
• Mice
• Molecular Weight
• Neoplasms, Experimental (analysis)
• Oligosaccharides (analysis)