Title : Carbohydrate microheterogeneity of rat
serotransferrin
Abstract :
- Determination of glycan primary structures and characterization of a new type of trisialylated diantennary glycan
- A previously established procedure [Regoeczi, E., Chindemi, P.A., Rudolph, J. R., Spik, G. & Montreuil, J. (1987) Biochem
- Cell Biol
- 65, 948-954] was used to isolate from three DEAE-cellulose chromatographic fractions of diferric rat serotransferrin ( rTf ) subpopulations having discernible affinities for concanavalin A ( ConA )
- These entities are designated rTf-1 (not retarded by ConA column), rTf-2 (retarded) and rTf-3 (bound)
- Each rTf type was found to be endowed with carbohydrate sufficient to account for a single diantennary glycan/protein molecule
- Glycan structures were determined on the glycopeptides by employing GLC/MS and 400-MHz 1H-NMR spectroscopy
- All glycans possessed a common, trimannosyl-N,N'-diacetylchitobiose core with or without one L-fucose alpha-1,6-linked to the Asn-linked GlcNAc
- However, there were differences in the antennae
- Thus, in rTf-3, both antennae were of the disialylated diantennary N-acetyllactosamine type which is frequently encountered in other plasma glycoproteins
- However, the alpha-1,3-Man-linked antenna in rTf-1 as well as rTf-2 had the sequence: Neu5Ac(alpha 2-3)Gal(beta 1-3)[Neu5Ac(alpha 2-6)]GlcNAc(beta 1-2)Man
- In addition, the alpha-1,6-Man-linked antenna deviated in rTf-2 from the standard structure by having the sequence: Neu5Ac(alpha 2-3)Gal(beta 1-3)GlcNAc(beta 1-2)Man
- The possible relevance of the above structures to the ConA binding of rTf is discussed
- A further preparation, obtained from the most anionic DEAE-cellulose fraction (peak V) or rTf contained several tetrasialylated diantennary glycans whose precise structures remain to be established in future studies
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. microheterogeneity, , serotransferrin, -, -
- 0. serotransferrin, , serotransferrin, Carbohydrate microheterogeneity, -
- 1. trisialylated, , -, trisialylated diantennary glycan, -
- 10. disialylated, , -, the disialylated diantennary N-acetyllactosamine type, -
- 10. glycoproteins, , glycoproteins, -, -
- 10. type, , rTf, type, -
- 11. antenna, , rTf-1, antenna, -
- 11. antenna, , rTf-2, antenna, -
- 11. sequence, , -, the sequence: Neu5Ac(alpha 2-3)Gal(beta 1-3)[Neu5Ac(alpha 2-6)]GlcNAc(beta 1-2)Man, -
- 12. sequence, , -, the sequence: Neu5Ac(alpha 2-3)Gal(beta 1-3)GlcNAc(beta 1-2)Man, -
- 14. contained, , rTf, several tetrasialylated diantennary glycans, -
- 14. tetrasialylated, , -, several tetrasialylated diantennary glycans, -
- 7. glycopeptides, , -, -, glycopeptides
- 8. Asn-linked, , -, the Asn-linked GlcNAc, Asn
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):