Crystallin is a transparent protein that makes up the lens of the human eye. This protein is water-soluble in structure, and has also been found in other parts of the body, such as the heart, and in some cancerous tumours. Crystallins make up 90% of water-soluble proteins in the lens of the eye.
There are three classifications of Crystallins in science: alpha, beta and gamma. Beta and gamma crystallins are similar in structure, and have been grouped under the name βγ-Crystallins. The alpha Crystallins are named α-crystallins; and together, these two “families” of Crystallins make up 90% of proteins in the eye lens, and 30% of proteins in the entire eye.
Research into crystallin is still ongoing; there have been significant breakthroughs in the last decade, particularly in determining the structure of Crystallin. In early 2020, researchers at the University of Munich determined the structure of Crystallin for the first time - the result of 40 years’ research. This allowed scientists to study any further uses of Crystallin, beyond what they already understood - and these findings helped to progress cataract treatment.
Primarily, Crystallin’s function is to give the eye refractive power. This means that the eye is able to take in and refract light, without obstructing it - hence the transparent structure of the protein. In essence, Crystallin is the protein that allows humans to see light in such a detailed way, as well as having metabolic and regulatory function too, scientists believe.