From the Research
Elastin is cross-linked by the enzyme lysyl oxidase, which produces desmosine and isodesmosine as the primary cross-linking products, as well as other cross-links such as lysinonorleucine and allysine aldol, resulting in a complex and heterogeneous molecular network. The cross-linking process involves the oxidative deamination of specific lysine residues in elastin molecules, converting them to allysine (an aldehyde), which then spontaneously condense with neighboring lysine residues to form the unique cross-links 1. The formation of these cross-links is essential for elastin's proper function, as it creates a three-dimensional network that provides tissues with elasticity and resilience. The products of this cross-linking process include desmosine, isodesmosine, lysinonorleucine, and allysine aldol, which are found almost exclusively in elastin.
Some key points to consider:
- The cross-linking process is catalyzed by members of the lysyl oxidase family, including LOX, LOXL1, LOXL2, LOXL3, and LOXL4 2.
- The cross-linking of elastin is a complex and heterogeneous process, involving multiple types of cross-links and molecular interactions 3.
- Deficiencies in lysyl oxidase activity or abnormal cross-linking can lead to connective tissue disorders characterized by decreased tissue elasticity, such as certain forms of cutis laxa or pseudoxanthoma elasticum 4.
- The cross-linking process is critical for the formation and maintenance of elastic fibers, which are essential for the elasticity and resilience of various organs, including blood vessels, lungs, skin, and ligaments 1.
In terms of the specific products of the cross-linking process, desmosine and isodesmosine are the primary cross-linking products, while lysinonorleucine and allysine aldol are also formed as a result of the cross-linking reaction. These cross-links are essential for the proper function of elastin and the maintenance of tissue elasticity and resilience.