Related Experiment Videos
Differences in LDL subspecies involve alterations in lipid composition and conformational changes in apolipoprotein B
J R McNamara1, D M Small, Z Li
1Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Journal of Lipid Research
|September 1, 1996
Summary
Smaller low-density lipoprotein (LDL) particles have altered composition, including less cholesterol and more triglycerides. These changes in LDL structure may affect receptor binding and oxidation resistance.
Area of Science:
- Lipid Metabolism
- Cardiovascular Science
- Biochemistry
Background:
- Low-density lipoprotein (LDL) particle size is a variable trait linked to cardiovascular risk.
- Understanding the compositional basis of LDL size variability is crucial for assessing lipoprotein function.
Purpose of the Study:
- To investigate the compositional differences in low-density lipoprotein (LDL) particles across a range of sizes.
- To determine how changes in LDL composition relate to particle size and potential functional implications.
Main Methods:
- Assessed LDL composition in plasma from 66 subjects using gradient gel electrophoresis to define eight discrete LDL sizes.
- Analyzed lipoprotein concentrations, specific proteins via immunoassay and electrophoresis.
- Calculated molecular weight, lipid and protein content, surface area, and core volume.
Main Results:
- Smaller LDL particles exhibited decreased anhydrous molecular weight, cholesteryl ester, free cholesterol, and phospholipid content.
- Triglyceride and protein content increased with decreasing LDL size.
- Calculations indicated altered surface lipid coverage, reduced core volume, and changes in apoB-100 structure with decreasing particle size.
Conclusions:
- LDL particle size is associated with significant compositional alterations, particularly in lipid and protein content.
- Conformational changes in apoB-100 are likely required to accommodate compositional shifts in smaller LDL particles.
- These structural modifications in LDL may influence LDL receptor binding affinity and susceptibility to oxidation.