Oct. 23, 2013 — The refractive power of the human eye lens relies on a densely packed mixture of proteins. Special protective proteins ensure that these proteins do not clump together as time passes. When this protective mechanism fails, the ocular lens becomes clouded -- the patient develops a cataract. Scientists at the Technische Universitaet Muenchen (TUM) have now resolved the activation mechanism of one of these protective proteins, laying the foundation for the development of new therapeutic alternatives.
The lens of the human eye is made up of a highly concentrated protein solution that imparts the eye its high refractive power. Yet, despite this high protein content the ocular lens must remain clear and transparent. To this end ocular lens cells have developed a remarkable strategy: They have thrown overboard the complex machinery present in all other cells of the human body for building up and breaking down proteins. Instead, lens proteins are created only once in a lifetime -- during embryonic development. They are as old as the organism itself. To make them last a lifetime, the proteins are kept permanently in a dissolved state. If they clump together, the lens clouds over and the patient gets cataracts.
Alternative to surgery
To date, this condition could only be treated surgically by replacing the clouded lens with an artificial one. However, if the precise mechanism by which lens proteins are kept in a dissolved state were understood, it would open up new avenues for treatment. So, how does the cell manage to keep the proteins soluble for so long? The magic lies in two proteins,
The lens of the human eye is made up of a highly concentrated protein solution that imparts the eye its high refractive power. Yet, despite this high protein content the ocular lens must remain clear and transparent. To this end ocular lens cells have developed a remarkable strategy: They have thrown overboard the complex machinery present in all other cells of the human body for building up and breaking down proteins. Instead, lens proteins are created only once in a lifetime -- during embryonic development. They are as old as the organism itself. To make them last a lifetime, the proteins are kept permanently in a dissolved state. If they clump together, the lens clouds over and the patient gets cataracts.
Alternative to surgery
To date, this condition could only be treated surgically by replacing the clouded lens with an artificial one. However, if the precise mechanism by which lens proteins are kept in a dissolved state were understood, it would open up new avenues for treatment. So, how does the cell manage to keep the proteins soluble for so long? The magic lies in two proteins,