The concept and research progress of corneal crystallin

Crystallin plays an important role in the maintenance of lens transparency, which can be divided into enzymatic cyrstallin and non-enzymatic crystallin.Recent researches showed that identical proteins, mainly the enzymatic crystallin, also existed in the cornea, which was important to maintain corneal transparency and normal structural stability of the eye.Corneal crystallin refers to a kind of water soluble protein of species specificity including enzymes crystallin, which has both function of enzymes and structure formation.Human corneal crystallin mainly consists of two kinds: aldehyde dehydrogenase (ALDH) and transketolase (TKT). Corneal crystallin can protect the inner ocular tissues from ultraviolet radiation induced damage through its specific conformation to absorb ultraviolet, and act as enzyme to metabolize toxic aldehydes, scavenging reactive oxygen species, thus maintaining corneal transparency.Besides, the presence of some corneal crystallin in nuclear suggests a role in cellular growth regulation.This article aimed to review the current research and progress in the concept, category, structure, distribution and function of corneal crystallin.