Corpus: Elastin

Elastin' is an elastic fibre protein consisting of polypeptide subunits. It is one of the most important structural proteins in the human body.

Elastin is found to a large extent in the lungs, skin and blood vessels and gives these organs their characteristic properties - elasticity. It can be visualised in histological preparations, e.g. by Elastica van Gieson staining (EvG staining).

Elastin is a protein network and consists of cross-linked tropoelastin units. Tropoelastin is secreted by the cells in soluble form and then cross-linked by the enzyme lysiloxidase (LOX).

Elastin occurs in the body together with other structural proteins of the extracellular matrix (ECM), such as collagen. The combination of collagen and elastin makes the materials elastic and tear-resistant at the same time, as the properties of the two structural proteins complement each other.

Mammals have only one gene for tropoelastin, the ELN gene. The human ELN gene is an approximately 45 kb DNA segment on chromosome 7. It has 34 exons, which are interrupted by almost 700 introns. The first exon is a signal peptide that indicates the extracellular localisation of the protein.

Different tropoelastin variants are produced by alternative splicing in specific tissues. At least 11 isoforms are known in humans.

The fact that elastin is not produced during wound healing is one of the reasons for the low flexibility of scar tissue.