Photon correlation spectroscopy and light scattering of eye lens proteins at high concentrations

Abstract

The bovine eye lens protein, alpha L crystallin, has been studied with photon correlation spectroscopy and statical light scattering in the concentration range up to 200 g/l in different solvent conditions. At higher concentration (c greater than 70 g/l) the scattering behavior is quite complicated, which results in nonexponential correlation functions. Three methods have been used for the analysis of these correlation functions, namely, cumulant analysis, sum of two exponentials analysis, and exponential sampling method. These methods resulted in very similar results. The highly concentrated solutions contain two scattering entities: the single alpha L crystallin and a rather heterogeneous population of large clusters. The statical light-scattering experiments can be interpreted in the same way and gave consistent results for the dimensions of the large scattering units. The formation of these clusters, which are strong light scatterers, is superimposed on an increasing degree of correlation between the bulk of the alpha L-crystallins, resulting in a net decrease of light scattering as a function of concentration.

Light scattering by bovine alpha-crystallin proteins in solution: hydrodynamic structure and interparticle interaction

“…The formation of larger aggregates in a-crystallin solutions, on increasing the concentration of the protein, has been concluded from light scattering (Andries and Clauwaert, 1985). Nuclear magnetic relaxation dispersion measurements have also suggested the formation of large aggregates at a critical concentration of 15% of a-crystallin, similar to y1l-crystallin (Koenig et al, 1992).…”

“…a-Crystallin solutions have extensively been studied by light scattering (Andries and Clauwaert, 1985;Tardieu et al, 1986), photon correlation spectroscopy (Licinio and Delaye, 1988), x-ray scattering (Tardieu et al, 1987), osmotic pressure measurements , or a combination of these techniques .…”

AFM study of cytochrome CYP102A1 oligomeric state

“…Using PCS, it is possible to obtain the size distribution of macromolecules directly in solution. 8 In our work, this method…”

Photon correlation spectroscopy of light scattered by eye lenses in in vivo conditions

“…Because this part of g2(t) corresponds to the fastest decaying relaxation time present in the scattering sample, and considering the fact the a-crystallin is responsible for over 85% of the total scattering potential of the mammalian eye lens, it is assumed that this first decay component can be assigned to the diffusion of individual a-crystallin molecules. The value of the diffusion coefficient for the a-crystallins in the eye lens in vivo as found by cumulants however, is -2.5 times lower than the diffusion coefficient of the same molecules in a highly diluted solution (Andries and Clauwaert, 1985). This decrease is attributed to the diffusion hindering presence of a high concentration of at-crystallins as well as the 1Band -y-crystallins.…”