PMID: 2243102

 

    Legend: Sugar

Title : The polylactosaminoglycans of human lysosomal membrane glycoproteins lamp-1 and lamp-2

Abstract :
  1. Localization on the peptide backbones
  2. Lysosome membrane glycoproteins , lamp-1 and lamp-2 , have been shown to contain 18 and 16 N-glycans , some of which are modified by poly-N-acetyl-lactosamine
  3. We have localized the polylactosaminoglycans to specific sites on lamp-1 and lamp-2 purified from human chronic myelogenous leukemia cells
  4. Polylactosaminoglycan-containing glycopeptides , obtained by trypsin, pepsin, and V8 protease digestion of the glycoproteins , were isolated by Datura stramonium agglutinin affinity chromatography, gel filtration, and reverse phase high performance liquid chromatography
  5. The poly-N-acetyllactosaminyl structures of isolated glycopeptides were confirmed by the susceptibility of their released oligosaccharides to endo- beta-galactosidase
  6. Amino acid analysis and sequencing demonstrated that polylactosaminoglycans were located at Asn-34, Asn-93 and/or Asn-102, and Asn-195 and/or Asn-200 in lamp-1 , and at Asn-4 and/or Asn-10, and Asn-279 in lamp-2
  7. These results indicated that only certain glycosylation sites can be selectively modified by poly-N-acetyllactosamine , and those sites may confer the requirement by beta 1---- 3-N-acetylglucosaminyl transferase