Site-Specific Antagonists to Tetrodotoxin and Saxitoxin
Abstract
Towards the aim of developing rationally designed site-specific antagonists to tetrodotoxin (TTX) and saxitoxin (STX),the physical dimensions of the binding site and some key anchoring site-points in it for TTX and STX have been deduced from studies of structure-activity relations of analogues of these toxin molecules. The binding site is probably a pocket in the sodium-channel protein 9.5 A wide, 6 A tall, and 5 A deep, containing one ion-pairing and 4 hydrogen-bonding sites common to both TTX and STX. There are 1 or 2 sites unique to either toxin. If glutamate 387 of rat brain sodium channel were taken as the anionic site a of this work, then the carbonyl oxygen of asparagine 388 would be the hydrogen-bonding sites b and c. We have oxidized TTX to 11-oxoTTX, an important synthon for other TTX derivatives. From it, we have made a specifically labelled 3 HTTX of high specific activity, which is being used in attempts to locate the TTX binding site directly. Based on our present knowledge of the TTX/STX binding site, other compounds are now being synthesized to attempt to bind to some of the identified site-points for possible use as antagonists to TTX and STX.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1991
- Accession Number
- ADB156671
Entities
People
- C. Y. Kao
Organizations
- State University of New York