Title : Oligosaccharide analysis and molecular modeling of soluble forms of
glycoproteins belonging to the Ly-6, scavenger
receptor , and immunoglobulin superfamilies expressed in Chinese hamster ovary cells
Abstract :
- Most cell surface molecules are glycoproteins consisting of linear arrays of globular domains containing stretches of amino acid sequence with similarities to regions in other proteins
- These conserved regions form the basis for the classification of proteins into superfamilies
- Recombinant soluble forms of six leukocyte antigens belonging to the Ly-6 (CD59 ), scavenger receptor ( CD5 ), and immunoglobulin ( CD2 , CD48 , CD4 , and Thy-1 ) superfamilies were expressed in the same Chinese hamster ovary cell line, thus providing an opportunity to examine the extent to which N-linked oligosaccharide processing might vary in a superfamily-, domain-, or protein-dependent manner in a given cell
- While we found no evidence for superfamily-specific modifications of the glycans, marked differences were seen in the types of oligosaccharides attached to individual proteins within a given superfamily
- The relative importance of local protein surface properties versus the overall tertiary structure of the molecules in directing this protein-specific variation was examined in the context of molecular models
- These were constructed using the 3D structures of the proteins , glycan data from this study, and an oligosaccharide structural database
- The results indicated that both the overall organization of the domains and the local protein structure can have a large bearing on site-specific glycan modification of cells in stasis
- This level of control ensures that the surface of a single cell will display a diverse repertoire of glycans and precludes the presentation of multiple copies of a single oligosaccharide on the cell surface
- The glycans invariably shield large regions of the protein surfaces although, for the glycoproteins examined here, these did not hinder the known active sites of the molecules
- The models also indicated that sugars are likely to play a role in the packing of the native cell surface glycoproteins and to limit nonspecific protein-protein interactions
- In addition, glycans located close to the cell membrane are likely to affect crucially the orientation of the glycoproteins to which they are attached
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. glycoproteins, , glycoproteins, -, -
- 1. glycoproteins, , glycoproteins, -, -
- 10. glycoproteins, , glycoproteins, -, -
- 11. glycoproteins, , glycoproteins, -, -
- 4. attached, , proteins, oligosaccharides, -
- 6. proteins, , proteins, glycan data, -
- 9. glycoproteins, , glycoproteins, -, -
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):