Flotation rates, molecular weights and hydrated densities of the low‐density lipoproteins

Abstract A method involving three computer programs is described for characterizing the major component of the S f 0–12 low‐density lipoprotein class by its S f rate, hydrated density and molecular weight. All necessary information is obtained from a standard low and high‐density lipoprotein ultracentrifugal analysis. Moving‐boundary flotation rates are measured in 1.061 g/ml sodium chloride and 1.200 g/ml sodium bromide solutions and are corrected to flotation at zero concentration. Hydrated densities are calculated from η F o versus ρ plots and minimum hydrated molecular weights calculated using Stokes' frictional factor, assuming spherical molecules. Preliminary application of this procedure indicates higher S f o rates, higher molecular weights, and lower hydrated densities in females than in males. Molecular weights and standard deviations of the principal S f 0–12 component for non‐fasting normal adult females and males were 2.36±0.16 and 2.12±0.20 millions, respectively.