Fig. 1.

Effect of peroxynitrite exposure on the recognition of native epitopes on perlecan by monoclonal antibodies. Surface absorbed perlecan (10 nM) was treated with buffer (Pln), decomposed peroxynitrite (dONOO, 10 μM) or peroxynitrite (ONOO, 10 μM) at 22 °C for 20 min in 0.1 M phosphate buffer, pH 6.5 in the absence (black bars) and presence (light grey bars) of NaHCO₃ (25 mM). The perlecan was then probed by ELISA using monoclonal antibodies (mAbs) against HS epitopes: (A) mAb 10E4; (B) mAb HepSS-1; (C) mAb JM403 and protein core epitopes: (D) perlecan domain I (mAb CSI-076); (E) perlecan domain III (mAb 7B5); and (F) perlecan domain V (mAb CSI-074). Data are expressed as a percentage of the untreated proteoglycan ELISA signal, and are means ± SEM of values obtained from triplicate wells from n ≥ 3 independent experiments. Data were analyzed by 2-way ANOVA, with statistical significance assumed at p < 0.05; a different to perlecan control, b different to dONOO, * significantly different to experiments carried out in the absence of NaHCO₃.