FIG. 8.

Effects of pH and β-mercaptoethanol on reactivity of the GBV-C anti-E2 MAb with synthetic peptides. (A) Synthetic 13-mers with and without a biotinylation adaptor (Bi) were applied to microtiter plate wells in PBS (p; pH 7.0), borate (b; pH 8.3), or carbonate (c; pH 9.6) buffer. The 13-mer (GGAGLTGGFYEPL) lacking Bi did not react at all (open triangles), whereas the same peptide with Bi (solid triangles) reacted well. pH altered the binding of the 13-mer featuring C-terminal Cys₄₉₇ and lacking Bi (open squares) but not that of the same peptide featuring Bi (solid squares). (B) M6 reactivity with the C-terminally truncated peptide A14R was not altered by reducing (r) with β-mercaptoethanol. However, the reduced peptide containing C-terminal Cys₄₉₇ (L13C-r) demonstrated significantly less reactivity with M6 than nonreduced L13C did.