Fig. 1.

The effect of 4F on SMase-induced LDL aggregation during coincubation. LDL particles (1 mg/ml) were modified with bcSMase in the absence or presence of the indicated molar ratios of peptide to apoB-100 at pH 7.0. The aggregation of the LDL particles was monitored by measuring the turbidity (A) and by SEC (B). The inset in B shows quantitative analysis of protection of L-4F against SMase-induced LDL aggregation at 3 and 6 h time points based on the SEC data. The sizes of the LDL particles were measured using DLS (C) at the indicated time points. The SMase-induced formation of phosphorylcholine was determined by an Amplex Red assay (D). The results represent means ± SD of triplicate wells and are representative of four independent experiments performed with different LDL preparations.