Enhanced laminin binding by α-dystroglycan after enzymatic deglycosylation

Ariana C. Combs, James M. Ervasti

Research output: Contribution to journalArticlepeer-review

64 Scopus citations

Abstract

Carbohydrate modifications are clearly important to the function of α-dystroglycan but their composition and structure remain poorly understood. In the present study, we describe experiments aimed at identifying the α-dystroglycan oligosaccharides important for its binding to laminin-1 and carbohydrate-dependent mAbs (monoclonal antibodies) IIH6 and VIA4 1. We digested highly purified skeletal muscle α-dystroglycan with an array of linkage-specific endo- and exoglycosidases, which were verified for action on α-dystroglycan by loss/gain of reactivity for lectins with defined glyco-epitopes. Notably, digestion with a combination of Arthrobacter ureafaciens sialidase, β(1-4)galactosidase and β-N- acetylglucosaminidase substantially degraded SiaAα2-3Galβ1- 4GlcNAcβ1-2Man glycans on highly purified α-dystroglycan that nonetheless exhibited enhanced IIH6, VIA41 and laminin-1 binding activity. Additional results indicate that α-dystroglycan is probably modified with other anionic sugars besides sialic acid and suggest that rare α-linked GlcNAc moieties may block its complete deglycosylation with currently available enzymes.

Original languageEnglish (US)
Pages (from-to)303-309
Number of pages7
JournalBiochemical Journal
Volume390
Issue number1
DOIs
StatePublished - Aug 15 2005

Keywords

  • Deglycosylation
  • Laminin
  • Lectin
  • Muscular dystrophy
  • Oligosaccharide structure
  • α-dystroglycan

Fingerprint Dive into the research topics of 'Enhanced laminin binding by α-dystroglycan after enzymatic deglycosylation'. Together they form a unique fingerprint.

Cite this