PMID: 1991473

 

    Legend: Gene, Sites

Title : NMR investigations of the N-linked oligosaccharides at individual glycosylation sites of human lutropin

Abstract :
  1. Human lutropin or luteinizing hormone ( hLH ) is a heterodimeric glycoprotein , composed of two subunits
  2. hLH alpha (N-glycosylated at Asn52 and Asn78 ) and hLH beta (N-glycosylated at Asn30 )
  3. The sugar chains were liberated by hydrazinolysis from intact hLH beta and from glycopeptides obtained after tryptic digestion of hLH alpha , subsequently reduced and fractionated as alditols by anion-exchange and ion-suppression amine-adsorption HPLC and identified mainly by one-dimensional (1D) and two-dimensional (2D) 1H-NMR spectroscopy
  4. The results indicate predominantly diantennary
  5. N-acetyllactosamine-type structures at all three glycosylation sites
  6. The oligosaccharides attached to Asn52 ( hLH alpha ) and Asn30 ( hLH beta ) show a remarkably similar pattern, with mainly chain-terminating 4-sulphated 2-deoxy-2-N-acetylamino-D-galactose (GalNAc) and a sulphated/sialylated structure as the major single component
  7. However, virtually all N-glycans on the beta subunit bear a fucose residue alpha 1-6-linked to the proximal GlcNAc, whereas those at Asn52 (and Asn78 ) of the alpha subunit are predominantly non-fucosylated
  8. The oligosaccharides at Asn78 ( hLH alpha ) are sialylated rather than sulphated and contain the unique sequence NeuAc alpha 2-6 GalNAc beta 1-4GlcNAc beta 1-2 Man alpha 1-3 as part of the majority of mono- and disialylated compounds
  9. The major single constituent at Asn78 has the following structure: [formula, see text
Output (sent_index, trigger, protein, sugar, site):
  • 0. glycosylation, , lutropin, -, sites
  • 1. glycoprotein, , glycoprotein, -, -
  • 1. glycoprotein, , luteinizing hormone, -, -
  • 1. glycoprotein, , lutropin, -, -
  • 2. N-glycosylated, , -, -, Asn52 and Asn78
  • 2. N-glycosylated, , hLH alpha, -, Asn52 and Asn78
  • 2. N-glycosylated, , hLH beta, -, Asn30
  • 3. glycopeptides, , -, -, glycopeptides
  • 3. liberated, , hLH beta, The sugar chains, glycopeptides
  • 6. attached, , hLH alpha, The oligosaccharides, Asn30
  • 6. attached, , hLH alpha, The oligosaccharides, Asn52
  • 6. attached, , hLH beta, The oligosaccharides, Asn30
  • 6. attached, , hLH beta, The oligosaccharides, Asn52
  • 6. sulphated/sialylated, , -, a sulphated/sialylated structure, -
  • 7. N-glycans, , subunit, N-glycans, -
  • 8. Asn78, , -, The oligosaccharides, Asn78
  • 8. sequence, , -, the unique sequence NeuAc alpha 2-6 GalNAc beta 1-4GlcNAc beta, -
  • 8. sialylated, , -, The oligosaccharides, -
Output(Part-Of) (sent_index, protein, site):
  • 0. lutropin, sites
  • 6. hLH alpha, Asn52
  • 6. hLH beta, Asn30
  • 7. subunit, Asn52
  • 7. subunit, Asn78
  • 8. hLH alpha, Asn78
*Output_Site_Fusion* (sent_index, protein, sugar, site):
  • 2. hLH alpha, -, Asn52 and Asn78
  • 2. hLH beta, -, Asn30
  • 6. hLH alpha, The oligosaccharides, Asn30
  • 6. hLH alpha, The oligosaccharides, Asn52
  • 6. hLH beta, The oligosaccharides, Asn30
  • 6. hLH beta, The oligosaccharides, Asn52
  • 8. hLH alpha, The oligosaccharides, Asn78

 

 

Protein NCBI ID SENTENCE INDEX
hLH alpha 1081 2,3,6,8
hLH beta 3972 2,3,6