Structural studies on LDL from patients with high and low lipoprotein (a)

Background and Aims : To map LDL total fraction ultrastructure as a function of composition, in terms of lipid serum profiles and presence of lipoprotein (a).Methods: LDL ultrastructure is secured via Small Angles X-Ray Scattering (SAXS) and the use of the semianalytical super ellipsoid of the revolution model. Blood samples were obtained from four male, adult individuals with different combinations of total cholesterol (TC)-triglyceride (TGA) serum levels, respectively: low/low, high/low, low/high, and high/high. Two of them have high Lp(a) levels and the other two have low. LDL total, large buoyant, and small dense subfractions were isolated by ultracentrifugation. SAXS data were collected on these samples in TBS buffer at 8, 25, and 37 °C in the P12 beamline at EMBL, Hamburg. This enables to characterize of LDL structure below, at, and above the melting temperature of its cholesteryl ester-rich core. T-tests are performed to compare the data.Conclusions: The analysis by SAXS allowed us to determine the different parameters that describe the internal structure of the LDL particles (Radius, Ellipticity, etc). Finally, It was possible to establish the structural difference of LDL according to its Lp(a), TGA, and TC content. Background and Aims : To map LDL total fraction ultrastructure as a function of composition, in terms of lipid serum profiles and presence of lipoprotein (a). Methods: LDL ultrastructure is secured via Small Angles X-Ray Scattering (SAXS) and the use of the semianalytical super ellipsoid of the revolution model. Blood samples were obtained from four male, adult individuals with different combinations of total cholesterol (TC)-triglyceride (TGA) serum levels, respectively: low/low, high/low, low/high, and high/high. Two of them have high Lp(a) levels and the other two have low. LDL total, large buoyant, and small dense subfractions were isolated by ultracentrifugation. SAXS data were collected on these samples in TBS buffer at 8, 25, and 37 °C in the P12 beamline at EMBL, Hamburg. This enables to characterize of LDL structure below, at, and above the melting temperature of its cholesteryl ester-rich core. T-tests are performed to compare the data. Conclusions: The analysis by SAXS allowed us to determine the different parameters that describe the internal structure of the LDL particles (Radius, Ellipticity, etc). Finally, It was possible to establish the structural difference of LDL according to its Lp(a), TGA, and TC content.