... (3823.5 Da), was isolated from thevenom of the scorpion Androctonus mauretanicus. It showed94% sequence homology with Aa1 from Androctonus aus-tralis and 91% with BmTX3 from Buthus martensi which,respectively, ... were from Sigma. a-Den-drotoxin (DTX) was obtained as described [11]. UV gradeacetonitrile was from Fisons Scientific, trifluoroacetic acid, from Baker, and all other analytical reagents, from ... wererecently isolated from scorpion venoms: Aa1, from Andr-octonus australis, which was shown to block an A-type K+channels in cerebellar granular cells [7] and BmTX3, from Buthus martensi...