The high-affinity binding of Clostridium botulinum type B neurotoxin to synaptotagmin II associated with gangliosides GT1b/GD1a.
125I-labeled botulinum type B neurotoxin was shown to bind specifically to recombinant rat synaptotagmins I and II. Binding required reconstitution of the recombinant proteins with gangliosides GT1b/GD1a. Scatchard plot analyses revealed a single class of binding site with dissociation constants of 0.23 and 2.3 nM for synaptotagmin II and synaptotagmin I, respectively, values very similar to those of the high- (0.4 nM) and low-affinity (4.1 nM) binding sites in synaptosomes. The high-affinity binding of neurotoxin to synaptosomes was specifically inhibited by a monoclonal antibody recognizing with the amino-terminal region of synaptotagmin II. These results suggest that this region of synaptotagmin II participates in the formation of the high-affinity toxin binding site by associating with specific gangliosides.
Nishiki
T
T
Department of Veterinary Science, College of Agriculture, University of Osaka Prefecture, Japan.
Tokuyama
Y
Y
Kamata
Y
Y
Nemoto
Y
Y
Yoshida
A
A
Sato
K
K
Sekiguchi
M
M
Takahashi
M
M
Kozaki
S
S
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000915:Antibody Affinity; D001665:Binding Sites; D001905:Botulinum Toxins / Q000276:immunology / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D003014:Clostridium botulinum / Q000737:chemistry*; D000939:Epitopes; D005732:Gangliosides / Q000378:metabolism*; D008433:Mathematics; D008562:Membrane Glycoproteins / Q000378:metabolism; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism; D050863:Synaptotagmin I; D050861:Synaptotagmin II; D050857:Synaptotagmins
D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D000939:Epitopes; D005732:Gangliosides; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D050863:Synaptotagmin I; D050861:Synaptotagmin II; C494312:Syt1 protein, rat; C494264:Syt2 protein, rat; C021298:ganglioside, GD1a; D050857:Synaptotagmins; C016481:trisialoganglioside GT1; D001905:Botulinum Toxins