A benzene-1,3,5-tricarboxylamido-bridged tri(b-cyclodextrin) and its Zn2+ complex 2 are synthesized. Inclusion complexations of 2 with admantane derivatives give three supramolecular triads formed by tri(b-cyclodextrin), Zn2+ and admantane derivatives. Their carboxypeptidase activities and conformational mutating abilities under different pH were explored by ninhydrin colorimetric and circular dichroism spectrometric studies, and the possible mechanism was discussed. The results show that the 1/Zn2+/1-adamantaneacetic acid system gave the highest enzymatic activity up to 10.43 U·mg-1at a neutral condition.

Key words: bridged tri(b-cyclodextrin), admantane derivatives, supramolecular triad, carboxypeptidase A, enzyme mimic