elastic fiber (yellow fiber)

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Function

fibers can stretch up to 1.5 times their length, & snap back to their original length when relaxed

Formation:

formed from the elastic microfibril (consisting of numerous proteins including:
- microfibrillar-associated glycoproteins fibrillin, fibullin
- elastin receptor
- amorphous elastin
the microfibril scaffolds & organizes the deposition of amorphous elastin
amorphous elastin forms from monomers of soluble tropoelastin which is insolubilized & crosslinked into amorphous elastin by lysyl oxidase
lysyl oxidase reacts with specific Lys by oxidative deamination generates reactive aldehydes & allysine
reactive aldehydes and allysines can react with lysine & other allysine residues to crosslink & form desmosine, isodesmosine, & a number of other polyfunctional crosslinks that join surrounding elastin molecules to build an elastin matrix & elastic fiber
crosslinks are responsible for elastin's elasticity.

elastic fibers stain well with aldehyde fuchsin, orcein, & Weigert's elastic stain in histological sections.
permanganate-bisulfite-toluidine blue reaction is a highly selective & sensitive method for demonstrating elastic fibers under polarizing optics; the induced birefringence demonstrates the highly ordered molecular structure of the elastin molecules in the elastic fiber, not visible with standard optics.

Cutis laxa & Williams syndrome have elastic matrix defects associated with alterations in the elastin gene.
Buschke-Ollendorff syndrome, Menkes disease, pseudoxanthoma elasticum, & Marfan's syndrome have been associated with defects in copper metabolism & lysyl oxidase or defects in the microfibril (defects in fibrillin, or fibullin).
Hurler disease, a lysosomal storage disease, is associated with an altered elastic matrix
hypertension & some congenital heart defects are associated with alterations in the great arteries, arteries, & arterioles with alterations in the elastic matrix.