Binding characteristics of BoNT/A8 cell-binding domain H_C.

<p>(A) Binding affinity of H_CA8 to its synaptic protein receptor rat SV2C in a GST pull-down assay is similar to H_CA1. 12.5% SDS-PAGE and Coomassie staining of a representative pull-down experiment. (B) Densitometric quantification of bound H_C-fragments from (A) (n = 4 ± SD). (C) Competition assay: Binding of ³⁵S-H_CA1 to synaptosomes at 4°C in the presence of increasing amounts of recombinant H_CA1 or H_CA8, respectively. Bound ³⁵S-H_CA1 was detected by SDS-PAGE and autoradiography (n = 3 ± SD; H_CA1: EC₅₀ = 24 nM (95% CI 20–29 nM), H_CA8: EC₅₀ = 56 nM, 95% CI 43–72 nM)).