... mutant toxins and the analysis of their binding activity to the receptor toinvestigate the role of mutated amino acid residues; (b) the analysis of the influence of the modification of the cysteine ... sequence of the oligomeric band usingS373C, and obtained the two sequences GIFGP and GPSQW. These are sequences from residues 66 and 69, respectively, both of which are located in the loopAB200116976612 ... suggest that the binding region is located on or around (365)LYR-RIILG(372), R311, N376, G442 and Y445 (Figs 2, 4 and 5), and therefore loops 1, 2 and 3 (especiallyloop 2) are good candidate...