Elasticin

Elastin is a key protein in the extracellular matrix that provides elasticity to many tissues, such as arteries, lungs, and skin. It is a highly cross-linked, hydrophobic protein that can stretch and recoil like a rubber band, enabling tissues to resume their original shape after being deformed. Elastin is synthesized as a soluble precursor called tropoelastin, which is then secreted into the extracellular space. There, tropoelastin molecules assemble into microfibrils and are cross-linked by enzymes, primarily lysyl oxidase, forming the insoluble, functional elastin fibers.

The unique elastic properties of elastin are attributed to its amino acid composition, which is rich in glycine, alanine, valine, and proline, and its extensive covalent cross-linking. These cross-links, primarily desmosine and isodesmosine, are formed from the oxidative deamination of lysine residues and create a complex three-dimensional network. This network allows elastin to undergo significant reversible deformation.

Loss of elastin function or its degradation is associated with various aging processes and diseases. For example, the decline in skin elasticity with age is partly due to the breakdown of elastin fibers. In cardiovascular diseases, changes in arterial elastin can affect blood pressure regulation and vascular compliance. Genetic mutations affecting elastin production or function can lead to conditions like supravalvular aortic stenosis and cutis laxa. Research into elastin is ongoing to understand its role in health and disease and to explore therapeutic strategies for conditions involving elastin dysfunction.