Leucine Aminopeptidase, microsomal from porcine kidney

Leucine Aminopeptidase (LAP) is a proteolytic enzyme. It is an amino acid hydrolase that catalyzes the hydrolysis of leucine residues from the amino-terminal of proteins or peptides. LAP is naturally present in the liver, kidney, lung, and serum.

Leucine Aminopeptidase has been used:

• in proteomics analysis
• as a treatment for protein depolymerization reaction
• to test its effect on the degradation of human recombinant IL-8

Leucine Aminopeptidase serves as a biomarker for drug-induced liver injury because in case of liver injury, cirrhosis, hepatitis, and other disorders serum LAP activity increases. Abnormal expression of LAP results in tumor cell proliferation, angiogenesis, and invasion, so it can also serve as a cancer-related biomarker.

One unit will hydrolyze 1.0 μmole of L-leucine-p-nitroanilide to L-leucine and p-nitroaniline per min at pH 7.2 at 37 °C. (At 25 °C, approx. 40% of the activity at 37 °C is obtained.) The activity obtained using L-leucine p-nitroanilide as substrate is 2-5 times that obtained with L-leucinamide as substrate.