Inaction of saxitoxin-oximes on the sodium channel of frog skeletal muscle fibers.
Three oximes of saxitoxin, saxitoxin oxime, saxitoxin methyloxime, and saxitoxin carboxymethyloxime, were synthesized in which the oxime functions replaced the ketone function on C-12 of saxitoxin. On the voltage-clamped single frog muscle fibers these oximes were very weak or inactive in blocking the sodium channel. The results indicate that the hydrated ketone function in saxitoxin is essential for blockade of the sodium channel, probably through a hydrogen bonding mechanism with some receptor groups.
D000818:Animals; D001665:Binding Sites; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D010091:Oximes / Q000494:pharmacology; D011896:Rana temporaria; D012530:Saxitoxin / Q000031:analogs & derivatives / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D013329:Structure-Activity Relationship
D007473:Ion Channels; D010091:Oximes; D012530:Saxitoxin; D012964:Sodium