FIG 8 .

VHH-B8-LTIIa protects neurons from BoNT/A but not BoNT/B intoxication. (A) BoNT/A or BoNT/D (0.5 nM) with or without 20 nM VHH-B8-LTIIa (B8) was incubated with rat cortical neurons at 37°C for 24 h, when neurons were washed with PBS, lysed with radioimmunoprecipitation assay buffer, and separated by SDS-PAGE. WB was performed using anti-SNAP25 antibody (recognizing full-length and cleaved SNAP25) and VAMP2 (recognizing only full-length VAMP2) and β-actin (loading control [ctl]). (B) SNAP25 cleavage was quantified by measuring the SNAP25c/SNAP25 density ratios from three independent experiments. Data were analyzed by two-tailed Student’s t test. *, P < 0.05.