Hydrolysis of Di- and Oligopeptides by Human Liver Arylamidase

Arylamidase catalyzed hydrolysis of a variety of dipeptides and oligopeptides was investigated. The N-terminal residue must be an α-amino acid of the L-configuration. The penultimate residue must also be of the L-configuration. Substrates with straight or γ-branched nonpolar side chains on the N-terminal residue were most susceptible to arylamidase catalyzed hydrolysis. Substrates with β-branched or polar side chains on the N-terminal residue were quite resistant to arylamidase catalyzed hydrolysis. Substrates having nonpolar side chains on the penultimate residue were hydrolyzed quite rapidly regardless of the branch point. Amino acid amides are hydrolyzed by arylamidase.