Six cyclic peptides with 5, 7, 9, 11, 13, and 15 amino acids, with the
inhibitory sequence of the alpha-amylase inhibitor tendamistat, were
synthesized. The 11-residue peptide inhibited porcine pancreatic alpha
-amylase most potently (K-i 0.29 +/- 0.09 mu M). For the 11-residue pe
ptide, the circular dichroism study suggested a preliminary relationsh
ip between its inhibitory activity and structural property.