Binding Assays for the Quantitative Detection of P. brevis Polyether Neurotoxins in Biological Samples and Antibodies as Therapeutic Aids for Polyether Marine Intoxication
Abstract
The polyether lipid-soluble toxins isolated from the marine dinoflagellate Ptychodiscus brevis (formerly Gymnodinium breve bind to a unique site, Site V, associated with voltage-dependent sodium channels in rat brain synaptosomes. Using tritiated PbTx-3 as a specific probe for binding a Site V, a K sub d of 2.9 nM and a Bmax of 6.8 pmoles/mg synaptosomal protein has been determined. Binding equilibria and displacement by unlabeled PbTx-3 occur in a comparable concentration range to that of saxitoxin (site I). Labeled toxin can be displaced in a competitive manner by any of the other 5 naturally-occuring toxins; the quantitative displacement ability of each appears to reflect individual potency in fish bioassay. Preliminary K sub i calculations have been made for four of the toxins. A comparison of ED50 in radioimmunoassay and ED50 in synaptosome binding for detection of toxins which possess the structural backbone of PbTx-3, the immunizing hapten. Thus, the two assays have quantitative applicability; the former with respect to potency and the latter with respect to structure. Preliminary experiments involving conversion of the radioimmunoassay to urease enzyme linked form have been successful. Keywords: Antibodies; Brevetoxin.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA191072
Entities
People
- Daniel G. Baden
Organizations
- University of Miami