Immunochemistry of scorpion toxins

Abstract

Peptide 19-28, a model of an antigenic region of Androctonus australis Hector toxin II, has a rigid .alpha.-helix structure in the native protein. It was used as immunogen either in the free form, or bound to bovine serum albumin (BSA) or linked to its synthesis support (macroporous polyacrylamide resin). Only the anti-(peptide-BSA) and the anti-(peptide-resin) antibodies recognized the native toxin. The use of short synthetic analogues of peptide 19 - 28 suggests a specificity difference in the two antipeptides. Anti-(peptide-BSA) recognizes probably two determinants localized at the C and N terminals of the peptide chain. Anti-(peptide-resin) preferentially recognizes the N-terminal extremity. Finally we showed that the .alpha.-helix region remains accessible to antipeptide 19-28 when the toxin is bound to its receptor.