Protein crosslinks

Protein crosslinks are covalent bonds that join two protein molecules or different segments of the same protein. They can form enzymatically, as with collagen maturation, or non-enzymatically through oxidation and glycation by sugars and reactive aldehydes. Pathological crosslinks accumulate in long-lived structural proteins like collagen, elastin, and crystallins, stiffening tissues. This contributes to vascular rigidity, skin ageing, cataracts, and reduced organ elasticity.