The Reaction Mechanism of Bovine Lens Leucine Aminopeptidase

We present a quantum mechanical/molecular mechanical (QM/MM) study using the AM1 Hamiltonian and
a flexible MM part on the mode of action of the bovine lens leucine aminopeptidase (blLAP), a cytosolic
exopeptidase that catalyzes the cleavage of the N-terminal amide bond of peptides. The reaction mechanism
of this ubiquitous enzyme has not yet been clarified completely, although some suggestions based on
crystallographic data have been made. One path of the several possibilities investigated was found to be
clearly the most favorable and in good agreement with experimental results. Besides the elucidation of the
functional roles of active-site residues, an estimation of the environment effects is given.