Fig. 3.

The 4F-pretreated LDL particles are resistant to SMase-induced LDL aggregation. LDL particles (2 mg/ml) were preincubated with and without L-4F at 10:1 molar ratio of 4F to apoB-100, followed by extensive dialysis. Control and 4F-pretreated LDL (1 mg/ml) were modified with bcSMase at pH 7.0, and the aggregation of the LDL particles was monitored by turbidity (A) and by SEC (B). The inset in B shows quantitative analysis of aggregation based on the SEC data. The sizes of the LDL particles were measured using DLS (C) at the indicated time points. The formation of phosphorylcholine was determined by an Amplex Red assay (D). The results are representative of three independent experiments performed with different LDL preparations.