Partial specific volume and preferential hydration of low density lipoprotein subfractions

Area of Science:

• Lipid Metabolism
• Biophysical Chemistry

Background:

• Low-density lipoprotein (LDL) subfractions are implicated in atherosclerosis.
• Characterizing these subfractions is crucial for understanding cardiovascular disease risk.

Purpose of the Study:

• To determine the partial specific volume (v-) for five LDL subfractions.
• To evaluate the preferential hydration of LDL subfraction 3.
• To characterize these highly atherogenic components of human plasma lipoprotein spectra.

Main Methods:

• Partial specific volume (v-) determined by density measurements and CHN analysis.
• Preferential hydration evaluated using NaCl/H2O and NaCl/NaBr/H2O solvent systems.
• Molecular densities and compressibility assessed at varying forces.

Main Results:

• Mean v- values ranged from 0.9550 to 0.9757 ml/g across LDL subfractions.
• Molecular densities (sigma) increased with subfraction number, from 1.0249 to 1.0471 g/ml.
• Preferential hydration of LDL subfraction 3 was higher in NaCl/H2O than in NaCl/NaBr/H2O.
• LDL subfractions exhibited significantly higher compressibility than the solvent.

Conclusions:

• The study provides key biophysical parameters for distinct LDL subfractions.
• Differences in density and hydration highlight variations in LDL composition and structure.
• Findings contribute to a better understanding of the atherogenic potential of LDL subfractions.