Low density lipoproteins from human ascites plasma. Characterization and degradation by sodium deoxycholate.

The low density lipoproteins (LDL) in human ascites plasma were separated into two sublcasses by ultracentrifugation. The chemical compositions of the two LDLs were determined. On a weight percentage basis, LDL1 contained cholesterol ester, 20.8%; cholesterol, 19.3%; triacylglycerol, 19.7%; phospholipid, 22.1%; and protein, 10.8%. LDL2 contained cholesterol ester, 21.6%; cholesterol, 14.5%; triacylglycerol, 20.1%; phospholipid, 20.6%; and protein, 18.0%. The relative content of triacylglycerol and the ratio of unesterified cholesterol to esterified cholesterol in both LDLs were very high compared to corresponding human serum LDLs. Following the treatment of these LDLs with 575 mg of sodium deoxycholate per 10 mg of lipoprotein protein, a triacylglycerol-protein rich fraction was obtained by gel filtration in the presence of a micellar concentration of the detergent.