Keratin 6A assembled hard keratins to form a more structurally resilient material. Both epithelial keratins and hard keratins can be further subdivided into type I (acidic) keratins and type II (neutral-basic) keratins. The genes for the type I keratins are located in a gene cluster on human chromosome 17q, whereas the genes for type II keratins are located in a cluster on human chromosome 12q (the exception being K18, a type I keratin located in the type II gene cluster). Keratin 6A (protein name K6A; gene name "KRT6A"), is a type II cytokeratin, one of a number of isoforms of keratin 6
Lysyl oxidase the aldehyde product, allysine. Molecular oxygen and the copper ion are utilized to reoxidize the cofactor and yield another imine, producing hydrogen peroxide as a side product. Additional hydrolysis releases ammonia and the original cofactor, completing the catalytic cycle. Lysyl oxidase is an extracellular copper-dependent enzyme that catalyzes formation of aldehydes from lysine residues in collagen and elastin precursors. These aldehydes are highly reactive, and undergo spontaneous chemical reactions with other lysyl oxidase-derived aldehyde residues, or with unmodified lysine residues. This results in cross-linking collagen and elastin, which is essential for stabilization of collagen fibrils and for the integrity and