noun, plural: elastins
Elastin is a biomolecule that forms the elastic fiber. While collagen fiber is made up of collagen, elastic fiber is made up, primarily, of elastin. Another elastic fiber component is fibrillin. While elastin is amorphous, the fibrillin is fibrous.
Similar to collagen, elastin is also a glycoprotein. However, elastin has elastic properties. It can be stretched and then return to its initial shape afterwards. Thus, elastin enables the tissue in the body to be stretched (e.g. by pinching or poking) and then return to its original position.
Most of the amino acids in elastin are residues of glycine and proline. Cross linking depends upon the formation of desmosine from four lysine side groups. The mechanical properties of elastin are poorer in old animals.
While collagen molecule is made up of triple helix of tropocollagen, elastin is made up of tropoelastin protein molecules. The tropoelastins link together to form elastin.
In humans, elastin is encoded by the ELN gene on chromosome 7. Mutations involving this gene are associated with supravalvular aortic stenosis, cutis laxa, Marfan syndrome, atherosclerosis, Menkes syndrome, Buschke-Ollendorff syndrome, and Williams syndrome.