Spider venoms inhibit L-glutamate binding to brain synaptic membrane receptors.

Publisher Website
Google Scholar
Abstract
The venoms from 3 spider species, Araneus gemma, Neoscona arabesca and Argiope aurantia, were shown to inhibit the high-affinity, Na-independent L-Glu-binding sites in rat brain synaptic membranes. The same 3 venoms caused concentration-dependent inhibition of the activity of the Glu-binding glycoprotein purified from rat brain synaptic membranes. The venom milked from the glands of A. gemma was the most active inhibitor of L-Glu binding, causing 60-80% inhibition of both synaptic membrane and purified protein binding activity at 0.01 unit. The inhibitory activity of this venom was associated with a single protein peak obtained from gel permeation chromatography of the venom. The effect of the venom from A. gemma on the synaptic membrane glutamate-binding sites was slowly reversible. These observations indicate that the spider venoms have a direct effect on the recognition sites for L-Glu in brain synaptic membranes and that these sites are related to the physiologic Glu receptors.