Kinetic data analysis of chaperone-like activity of Wt, R69C and D109H αB-crystallins

The α-Crystallin (α-Cry) functions as a molecular chaperone, preventing the formation of stress-induced protein aggregation which is important for maintenance of lens transparency. The kinetic data of Wt, R69C and D109H αB-Crys chaperone-like activity were obtained by UV-Vis spectroscopy in both thermal- and chemical-induced aggregation methods. The data were analyzed using physical parameters describing the aggregation process including t* (the characteristic of the stage of nucleation), and t _0.5 (the characteristic of the stage of aggregate growth) and I _lim (the limiting value of the light scattering intensity). Parameter t* is duration of the lag phase and the lower t* value is associated with the higher rate of the nucleation stage. Also, the lower values of t _0.5 indicated the higher rate of aggregate growth stage. The change in parameter I _lim in the presence of chaperones can be connected with the change in the size of protein aggregates. These data are related to the research article entitled "Structural and functional characterization of D109H and R69C mutant versions of human αB-crystallin: the biochemical pathomechanism underlying cataract and myopathy development" [1].