What is elastase?

Definition

An elastase is the active form of an enzyme that is derived from the so-called proenzyme or zymogen proelastase by limited proteolysis. This means that by splitting off some amino acids the inactive form is converted into the active form. Elastase is an enzyme that can split the peptide bond between two amino acids in the middle of a protein by consuming water.

Typical substrates that are split include the protein elastin. There are several forms of elastase. There is granulocyte elastase, which occurs in certain immune cells, pancreatic elastase, which is produced by the pancreas, and other less well-known forms.

Task and function of elastase

Depending on its type, elastase has different tasks. The most common form of elastase, pancreatic elastase, which is produced by the pancreas, performs important tasks in digestion. The enzyme is responsible for part of the digestion of proteins that are taken in with food.

Like other enzymes that help digest proteins, pancreatic elastase splits the amino acid chain. In doing so, it is not opened from the ends, but acts within the chain. Thus, it belongs to the group of endopeptidases.

This splits proteins into several amino acid sequences, each of which has only a few amino acids in length. Thus, they are subsequently broken down by further enzymes, which occur in larger numbers, into individual amino acids, which can easily pass through the mucous membrane of the small intestine into the bloodstream. The enzymes that break down the chain of amino acids from the ends are called exopeptidases.

In addition to its effect in the intestine, the enzyme elastase can take over other tasks in the body, some of which are also harmful to the body. When certain diseases occur, the elastase can be found in the lung area and split the structural protein elastin. This structural protein is responsible, among other things, for the elasticity of the lungs, which can lead to functional restrictions if it is broken down.

In addition to pancreatic elastase, leukocyte elastase, also known as granulocyte elastase, is a widespread form of the enzyme. It occurs in special cells of the immune system, the granulocytes, and is particularly important in the defence against microorganisms. Without appropriate regulatory mechanisms, the function of elastase would last long enough, which would have negative effects on the human body.

The elastase could break down the body’s own proteins, which would then lose their function. This is the reason why the human body produces inhibitors that can reduce and cancel the activity of elastase. These are used, for example, in pancreatic elastase while the secretion of the pancreas is still in the excretory ducts. Here, the inhibitors prevent premature activation so that the body’s own tissue cannot be digested.