Related Experiment Video
Updated: Jul 31, 2026

Antigens Protected Functional Red Blood Cells By The Membrane Grafting Of Compact Hyperbranched Polyglycerols
Published on: January 2, 2013
[Relationship between proteoglycans and apoE on the HepG2 cell surface]
1Department of Pathology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China. pingliang@yahoo.com
Objective:
To characterize the associations and functions of apoE with the HepG2 cell surface through the study of the relationship between proteoglycans and apoE on HepG2 cell surface.
Methods:
The specific binding of 7C9, a monoclonal antibody against the N-terminal domain of apoE was employed to demonstrate the effects of glycosaminoglycans, heparinase, chondroitinase, xyloside, and chlorate on the apoE of HepG2 cell surface.
Results:
Growth of cells in beta-D-xyloside decreased cell surface apoE by 45% with a concomitant increase in apoE secretion (4.3-fold), underlining the importance of glycosaminoglycan association of apo E. Incubations with heparinase (3 U/ml) and heparin (1 mg/ml) decreased apoE by 25.0% and 30.5% respectively indicating association through cell surface haparin sulfate proteoglycans. Incubations with chondroitinase ABC (1.5 U/ml) reduced cell surface apoE by 40.0%. Chondroitin sulfate A and chondroitin sulfate B reduced cell surface apoE by 23.6% and 15.3% respectively while incubations with chondrointin sulfate C not effective. Decreasing the levels of cell surface apoE with haparin or chondrointin sulfates A and B increased the subsequent binding of LDL to the HepG2 cell surface.
Conclusions:
ApoE associates with the cell surface mainly through chondrointin sulfate proteoglycans and to a lesser extent through heparan sulfate proteoglycans, decreased levels of cell surface apoE increase the binding of LDL to the cell surface.
Related Concept Videos
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Protein Glycosylation
Glycosylation occurs in...
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
GPI Anchoring of Proteins in the ER Membrane
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Proteoglycans
Matrix Proteoglycans and Glycoproteins

