Organisation und Interaktionen der Augenlinsen Kristalline: Nativer Zustand und Cataract-Bildung

The human eye lens, as well as its vertebrate counterparts, is a unique and fascinating system from the point of view of colloid and polymer sciences. It owes its unique refractive-index properties and transparency to the exceptionally high protein concentration of sometimes more than 50% by weight. Three classes of proteins, termed a-, b-, and g-crystallins, coexist to essentially form a polydisperse colloidal dispersion that does not crystallize and is stabilized by specific intermolecular interactions. Age-related as well as inherited cataracts are thought to involve aggregation and/or crystallization, possibly even amyloid formation, that lead to larger aggregate structures inducing strong light scattering and thus opacity. However, as the scattering centers in lenses with cataract are extremely rare, there is as yet no molecular proof of this hypothesis. In fact, even the molecular basis of the stabilization of the native transparent lens structure is as yet not fully understood. One of the central aims of this project is to clarify whether the crystallins change their native (dilute-solution) structure when being concentrated, and to investigate in how far cataract formation involves conformational changes and possibly amyloid formation.