Amino Acid-β-Naphthylamide Hydrolysis by Pseudomonas aeruginosa Arylamidase

Abstract

The intracellular and constitutive arylamidase from Pseudomonas aeruginosa was purified 528-fold by salt fractionation, ion-exchange chromatography, gel filtration, and adsorption chromatography. This enzyme hydrolyzed basic and neutral N -terminal amino acid residues from amino-β-naphthylamides, dipeptide-β-naphthylamides, and a variety of polypeptides. Only those substrates having an l -amino acid with an unsubstituted α-amino group as the N -terminal residue were susceptible to enzymatic hydrolysis. The molecular weight was estimated to be 71,000 daltons. The lowest K m values were associated with substrates having neutral or basic amino acid residues with large side chains with no substitution or branching on the β carbon atom.