Abstract
Purpose: :
The purpose was to elucidate changes in crystallin profiles of a transgenic mouse model with deamidation of N at position 101 to D compared to wild type mice expressing WTαA.
Methods: :
Because relative to 5-month old WT mice with WT αA, the same aged transgenic mice with αAN101D showed cortical cataract development, the water soluble (WS)- and water insoluble(WI)-proteins from lenses of 5-month old from both type of mice were fractionated by a 2D-gel electrophoretic method and their protein profiles compared. The crystallin fragments with Mr <18 kDa and complexes >40 kDa were analyzed by mass spectrometric methods to determine their identity and post-translational modifications.
Results: :
The major difference in the crystallin profiles was that lenses from transgenic mice exhibited a greater number of crystallin fragments ((53 in number) compared WT (33 in number). Similarly, crystallin complexes with (Mr>40 kDa) were more abundant in lenses of transgenic mice compared to lenses of WT mice. The mass spectrometric analysis showed that both crystallin fragments and complexes were derived from alpha-, beta- and gamma-crystallins, and these also exhibited a variety of post-translational modifications.
Conclusions: :
Increased truncations of α-, β- and γ-crystallins and formation of their complexes occurred during cataract development in the lenses of 5-month old transgenic mice compared to WT mice. These crystallin fragments and their complexes might play an important role during cataract development in the transgenic mice.
Keywords: cataract • crystallins • protein modifications-post translational