Reduced Schiff base zinc complexes as proposed models of the active site of the dinuclear zinc enzyme A. Aminopeptidase

Khaleel A. Abu-Sbeih and Abdel

Abstract

Complexes of zinc with ligands prepared through the reduction of Schiff bases derived from salicylaldehyde and the primary aliphatic amines 1,4-diaminobutane (H2Salbn), 1,6-diaminohexane (H2Salhx), and tris(hydroxymethyl) aminomethane (H2Saltris) have been prepared and proposed as models of the active site of the zinc enzyme Aeromonas Proteolytica aminopeptidase. The complexes were characterized by 1H-NMR, FT-IR spectroscopy, and mass spectrometry. In complexes of both H2Salbn and H2Salhx, the 5-ccordinate zinc atoms are present in a N,O environment with bridging carboxylate ligands thus providing close analogues to the enzyme's active site. On the other hand, the complex of H2Saltris contains one zinc atom with an all-oxygen environment and one zinc atom bound to one N and five O atoms.