Interaction of botulinum type A, B and E derivative toxins with synaptosomes of rat brain.
Clostridium botulimum 125I-labelled derivative toxin immediately bound to rat synaptosomes. Of the two fragments of type B derivative toxin, the large-molecular-weight fragment (fragment I) inhibited the binding of labelled type B derivative toxin to synaptosomes in the same manner as unlabelled type B toxin did. The inhibition by the small-molecular-weight fragment (fragment II) was less than that by fragment I. These findings suggest that type B toxin binds to synaptosomes mainly with some part of fragment I. The binding of labelled type A and E derivative toxins was inhibited by either of the unlabelled type A or E derivative toxins, but not by type B derivative toxin. It is concluded that synaptosomes of rat brain possess relatively specific binding sites for botulinum toxin types.
D000818:Animals; D001905:Botulinum Toxins / Q000378:metabolism* / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008970:Molecular Weight; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D001905:Botulinum Toxins