Characterization of the P. brevis Polyether Neurotoxin Binding Component inExcitable Membranes

摘要

The development of a functional model, and topographic picture of how and whysodium channels act in the ways in which they gate sodium ion flux is our goal. We are developing about 20 different natural toxin derivatives based on 7 divergent chemical modifications. Each type of derivative has a specific potential once synthesized. Photoaffinity probes, affinity columns, tritiated non-exchangeable toxins, and specific intermediates are in various stages of completion. These probes are being utilized to characterize the topographic relationship of sites 1, 2, and 5 associated with voltage-sensitive sodium channels. The brevetoxin binding site has already been localized on Domain IV of VSSC, and binds to an external hydrophobic peptide located between S5 and S6 of Domain IV. Antisodium channel RIA, tritiated brevetoxin photoaffinity binding, immunoprecipitation, and SDS-polyacrylamide gel electrophoresis have all made substantial contributions to brevetoxin site localization.