Structures and biological activities of three synaptic antagonists from orb weaver spider venom.
The venom of Argiope aurantia, an orb weaver spider, contains a mixture of low molecular weight "argiotoxins", which block neuromuscular transmission in insects. Complete structure elucidation of three argiotoxins reveals common features; a hydrophilic, basic domain of arginine, a polyamine and asparagine is connected to an aromatic moiety contributed either by 4-hydroxyindole-3-acetic acid or 2,4-dihydroxyphenylacetic acid. Structural assignments of two argiotoxins are verified by chemical synthesis. The argiotoxins cause reversible paralysis when injected into insects and this is correlated with a stimulus-dependent inhibition of skeletal neuromuscular transmission at submicromolar concentrations.
Department of Entomology, University of California, Riverside 92521.
M E
ME
Adams
R L
RL
Carney
F E
FE
Enderlin
E T
ET
Fu
M A
MA
Jarema
J P
JP
Li
C A
CA
Miller
D A
DA
Schooley
M J
MJ
Shapiro
V J
VJ
Venema
D000818:Animals; D001180:Arthropod Venoms / Q000633:toxicity*; D006793:Houseflies; D007210:Indoleacetic Acids / Q000138:chemical synthesis / Q000302:isolation & purification / Q000633:toxicity*; D009682:Magnetic Resonance Spectroscopy; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D010648:Phenylacetates / Q000138:chemical synthesis / Q000302:isolation & purification / Q000633:toxicity*; D011073:Polyamines / Q000138:chemical synthesis / Q000302:isolation & purification / Q000633:toxicity*; D013111:Spider Venoms / Q000302:isolation & purification / Q000633:toxicity*; D013329:Structure-Activity Relationship; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D001180:Arthropod Venoms; D007210:Indoleacetic Acids; D010648:Phenylacetates; D011073:Polyamines; D013111:Spider Venoms; C558368:argiotoxin-636; C054143:argiotoxin 673; C054141:argiotoxin 659