Clinical Chemistry - Leucine Arylamidase

Leucine Arymalidase (LAP), or Leucine aminopeptidase is a proteolytic enzyme which is found in liver cells. It was given this name because it reacts most rapidly with leucine compounds. This enzyme is responsible for catalysing the hydrolysis of amino acid residues from the amino terminus of polypeptide chains.

LAP is released into the bloodstream when the liver cells become damaged in any way through infection or drugs and is an indicator of conditions such as carcinoma, jaundice, liver cirrhosis and pregnancy. LAP is more convenient than other blood tests, because unlike other liver enzymes, it can be measured in urine as well as serum or plasma.