Title : Carbohydrate structures of recombinant soluble human
CD4 expressed in Chinese hamster ovary cells
Abstract :
- Infection of T-lymphocytes and macrophages by human immunodeficiency virus (HIV) is mediated by the binding of the HIV envelope glycoprotein to the cell-surface receptor glycoprotein CD4
- A soluble, recombinant CD4 molecule ( rCD4 ), produced by expression of a truncated CD4 gene in Chinese hamster ovary (CHO) cells [Smith et al. (1987) Science 238, 1704-1707], is in clinical trials as a potential therapeutic agent in the treatment of acquired immunodeficiency syndrome (AIDS)
- In the present study, the structures of the Asn-linked oligosaccharides of soluble rCD4 have been elucidated
- The rCD4 molecule has two potential sites for N-glycosylation, Asn-271 and Asn-300
- Tryptic glycopeptides containing either of the sites were purified by reversed-phase HPLC, and their oligosaccharides were released enzymatically
- The structures of the oligosaccharides were determined by methylation analysis, high-pH anion-exchange chromatography, fast-atom bombardment mass spectrometry, and 1H NMR spectroscopy at 500 MHz
- Asn-271 was found to carry diantennary N-acetyllactosamine-type ("complex") oligosaccharides, of which 8% were asialo, 55% were monosialyl, and 37% were disialyl
- Approximately 18% of these structures contained fucose alpha(1-->6) linked to the reducing GlcNAc residue
- Two different hybrid structures were found to account for 34% of the oligosaccharides attached to Asn-300
- The remainder of the oligosaccharides attached to Asn-300 were diantennary N-acetyllactosamine-type, of which 10% were asialo, 61% were monosialyl, and 29% were disialyl
- Approximately 9% of the hybrid structures and 40% of the N-acetyllactosamine structures at Asn-300 were found to contain fucose alpha(1-->6) linked to the innermost GlcNAc residue
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. CD4, , CD4, Carbohydrate structures, -
- 1. glycoprotein, , glycoprotein, -, -
- 10. attached, , -, the oligosaccharides, Asn-300
- 11. Asn-300, , -, the N-acetyllactosamine structures, Asn-300
- 11. Asn-300, , -, the hybrid structures, Asn-300
- 3. Asn-linked, , -, the Asn-linked oligosaccharides, Asn
- 3. rCD4, , rCD4, the Asn-linked oligosaccharides, -
- 5. glycopeptides, , -, -, glycopeptides
- 7. carry, , -, diantennary N-acetyllactosamine-type ("complex") oligosaccharides, Asn-271
- 9. attached, , -, the oligosaccharides, Asn-300
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 10. CD4, the oligosaccharides, Asn-300
- 11. CD4, the N-acetyllactosamine structures, Asn-300
- 11. CD4, the hybrid structures, Asn-300
- 7. CD4, diantennary N-acetyllactosamine-type ("complex") oligosaccharides, Asn-271
- 9. CD4, the oligosaccharides, Asn-300