Elastase from human leukocytes

Elastase is a proteolytic enzyme. It is a member of the subgroup named, peptidyl peptide hydrolases. It is a major anatomic constituent of arteries. It is mainly found in the pancreas and pancreatic juice of various birds and mammals. It is also present in human serum, granulocytes and erythrocytes.

Leukocyte elastase is a 29 kDa serine endoprotease of the Proteinase S1 Family. It exists as a single 238 amino acid-peptide chain with four disulfide bonds. It contains two or thee N-linked glycans of variable composition which account for its three major isoforms.
Isoelectric point: pI = 8.77 - 9.55

Elastase from human leukocytes has been used:

• to measure serum elastase activity
• in proteolytic digestion of fibronectin and salivary glands
• in neutrophil elastase (NE) activity assay
• cell-free NE digestion of E-cadherin
• scratch wound assay
• in a study that determined that fragments of Nle3-angiotensin(1-7) accelerate healing in dermal models

Elastase has been used to digest fibronectin. The results were compared with fibronectin digestion by crude human leukocyte homogenate to examine the presence of fibronectin peptides in saliva of patients with Sjögren′s syndrome. It has also been used as a reference to determine the elastase activity in cell lysates. This study examined the effect of all-trans retinoic acid on procoagulant and fibrinolytic activities of cultured blast cells. These blast cells were from patients with acute promyelocytic leukemia.

Elastase enzyme is capable of releasing soluble peptides from insoluble elastin fibers with the help of a proteolytic process. It can stimulate disintegration of the axoneme with the help of adenosine triphosphate (ATP). Unlike pancreatic elastase the leukocyte enzyme has a preferential cleavage for the carboxyl side of valine, but will also cleave to a lesser extent after alanine. Natural substrates include elastin, cartilage proteoglycans, collagen types I, II, II and IV, and fibronectin.

Lyophilized from 0.05 M sodium acetate (pH 5.5) and 0.6 M NaCl

One unit will release one nanomole of p-nitrophenol per sec from BOC-L-alanine p-nitrophenyl ester at pH 6.5 at 37 °C.