Essential structure for full enterotoxigenic activity of heat-stable enterotoxin produced by enterotoxigenic Escherichia coli

Abstract

Several analogues of heat-stable enterotoxins (STh and STp) produced by enterotoxigenic Escherichia coli were synthesized. Peptides (STh[6-18] and STp[5-17]) consisting of 13 amino acid residues from the Cys residue near the N-terminus to the Cys residue near the C-terminus and linked by three disulfide bonds had the same biological and immunological properties as native STh and STp, respectively. The results indicated that the sequence with the 13 amino acid residues and three disulfide linkages is essential for full biological activity of ST.