Foffi, GiuseppeSavin, GabrielaBucciarelli, SaskiaDorsaz, NicolasThurston, George M.Stradner, AnnaSchurtenberger, Peter2014-12-302014-12-302014-12-30201410.1073/pnas.1406990111https://infoscience.epfl.ch/handle/20.500.14299/109657WOS:000345662700035We study the equilibrium liquid structure and dynamics of dilute and concentrated bovine eye lens alpha-crystallin solutions, using small-angle X-ray scattering, static and dynamic light scattering, viscometry, molecular dynamics simulations, and mode-coupling theory. We find that a polydisperse Percus-Yevick hard-sphere liquid-structure model accurately reproduces both static light scattering data and small-angle X-ray scattering liquid structure data from alpha-crystallin solutions over an extended range of protein concentrations up to 290 mg/mL or 49% vol fraction and up to ca. 330 mg/mL for static light scattering. The measured dynamic light scattering and viscosity properties are also consistent with those of hard-sphere colloids and show power laws characteristic of an approach toward a glass transition at alpha-crystallin volume fractions near 58%. Dynamic light scattering at a volume fraction beyond the glass transition indicates formation of an arrested state. We further perform event-driven molecular dynamics simulations of polydisperse hard-sphere systems and use mode-coupling theory to compare the measured dynamic power laws with those of hard-sphere models. The static and dynamic data, simulations, and analysis show that aqueous eye lens alpha-crystallin solutions exhibit a glass transition at high concentrations that is similar to those found in hard-sphere colloidal systems. The alpha-crystallin glass transition could have implications for the molecular basis of presbyopia and the kinetics of molecular change during cataractogenesis.alpha crystallinscatteringmode-coupling theorymolecular dynamicsglass transitiontext::journal::journal article::research article