Background: The adipocyte enhancer binding protein 1 is a transcriptional repressor with carboxypeptidase (CP) activity. This protein binds to a regulatory sequence, adipocyte enhancer 1 (AE-1), located in the proximal promoter region of the adipose P2 (aP2) gene, which encodes the adipocyte fatty-acid binding protein. It is characterized as a member of the regulatory B-like CP family. This protein seems to be activated by a novel mechanism, whereby the direct binding of DNA enhances its protease activity. Adipocyte-enhancer binding protein 1 may play a role in differentiated vascular smooth muscle cells.