Application of Purified Botulinum Type A Neurotoxin to Treat Experimental Trigeminal Neuropathy in Rats and Patients with Urinary Incontinence and Prostatic Hyperplasia
Figure 1
Progenitor L toxin structure. (a) Scheme indicating that (1) under alkaline conditions PTXs dissociate into an NTX and nontoxic components; (2) fully activated NTX is cleaved at a site in the N-terminus; (3) HA1 and HA3b bind galactose and sialic acid, respectively. (b) Predicted tertiary structure of type C and D L toxins and molar ratio of their (sub)components. Model is based on the structural data of Hasegawa et al. [8] and Nakamura et al. [7]. Three dimensional structure of HA1 and its binding sites for sugars are also shown. Both type A and C HA1 showed similar structures consisting of two β-trefoil domains conjugated by an α-helix. Two sugar-binding sites (I and II) on C-terminal β-trefoil domain are predicted and A-HA1 and C-HA1 binds to galactose via sites II and I, respectively. In the case of type C, HA1 also bound to sialic acid via site I [6].
