title: omega-Aga-I: a presynaptic calcium channel antagonist from venom of the funnel web spider, Agelenopsis aperta.
abstract: Spider venoms are proving to be important sources of specific ion channel toxins. Venom of Agelenopsis aperta, a funnel web spider, contains a class of polypeptide toxins which blocks neuromuscular synapses at nanomolar concentrations. Detailed physiological analyses of block caused by one of these toxins, omega-Aga-I, show that it suppresses transmitter release at insect and frog neuromuscular junctions and blocks calcium spikes in insect neuronal cell bodies. omega-Aga-I may define a binding site on neuronal calcium channels which is common to both vertebrates and invertebrates.
authors: Department of Entomology, University of California, Riverside 92521.
authors: V P
authors: VP
authors: Bindokas
authors: M E
authors: ME
authors: Adams
mesh_terms: D060848:Agatoxins; D000818:Animals; D001180:Arthropod Venoms / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D006110:Grasshoppers; D006793:Houseflies; D066298:In Vitro Techniques; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D011894:Rana pipiens; D013111:Spider Venoms / Q000302:isolation & purification / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology
chemical_list: D060848:Agatoxins; D001180:Arthropod Venoms; D002121:Calcium Channel Blockers; D013111:Spider Venoms; C060465:omega-agatoxin I; D002118:Calcium