PMID: 12927778

 

    Legend: Sugar

Title : Characterization of nucleotide pyrophosphatase-5 as an oligomannosidic glycoprotein in rat brain

Abstract :
  1. Membrane glycoproteins of neural cells play crucial roles in axon guidance, synaptogenesis, and neuronal transmission
  2. We have here characterized membrane glycoproteins containing terminal alpha-mannose residues residues in rat brain membranes
  3. Affinity purification using Galanthus nivalis agglutinin , that is highly specific for terminal alpha-mannose residues, revealed a 50-kDa protein as well as 80-kDa SHPS-1 and 45-kDa beta2 subunit of Na,K-ATPase in rat brain membranes
  4. Combination of N-terminal peptide sequencing and mass spectrometry indicated that the 50-kDa protein was rat nucleotide pyrophosphatase-5 (NPP-5 )
  5. In contrast to other NPPs , NPP-5 was a type-I transmembrane protein
  6. Northern blot analysis showed that NPP-5 was highly expressed in brain, but also expressed in other peripheral tissues
  7. However, we could not detect either the NPP activity or the lysophospholipase D activity in the immunoprecipitates with antibodies to NPP-5 from rat brain membranes
  8. These data, therefore, suggest that NPP-5 is a neural oligomannosidic glycoprotein that may participate in neural cell communications