Defensin promotes the binding of Lp(a) to HUVEC matrix. (A) ¹²⁵I-Lp(a) (20 nmol/L) or mixtures of defensin (10 μmol/L) plus ¹²⁵I-Lp(a) (20 nmol/L) were incubated with HUVEC matrix in the presence of buffer (□, ▩) or 20-fold molar excess cold Lp(a) () for 1 hour at 37°C, and the bound radioactivity was measured. The mean ± SD of 3 experiments is shown. This corresponds to an increase in bound Lp(a) from a mean of 2.9 fmol in the absence of defensin to 96 fmol in the presence of defensin. The mean ± SD of 3 experiments is shown. (B)¹²⁵I-Lp(a) (10 nmol/L) was incubated with HUVEC matrix in the presence of the indicated concentrations of defensin for 1 hour at 37°C, and the bound radioactivity was measured. The data are expressed relative to the binding of ¹²⁵I-Lp(a) alone. The mean ± SD of 3 experiments is shown.