title: Binding characteristics of a sea anemone toxin from Parasicyonis actinostoloides with crayfish leg nerves.
abstract: A sea anemone toxin from Parasicyonis actinostoloides which inhibits the inactivation process of the sodium channel was acylated by using cold or tritium labeled propionyl N-hydroxysuccinimide ester. Acylation changed the isoelectric point of the peptide but did not change the toxicity to the crayfish nerve. Propionyl-toxin bound to leg nerves with Kd of 310 nM and Bmax of 104 pmol/g of wet nerve. The binding affinity and physiological activity of the toxin to crayfish nerves were suppressed with a common dependence on membrane depolarizations induced by elevated external K+ concentrations.
mesh_terms: D000818:Animals; D003400:Astacoidea; D003064:Cnidarian Venoms / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials; D009474:Neurons / Q000378:metabolism*; D009498:Neurotoxins / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D012615:Sea Anemones
chemical_list: D003064:Cnidarian Venoms; D009498:Neurotoxins; D011188:Potassium