PURPOSE: The purpose was to characterize the properties of a proteinase activity associated with betaA3-crystallin, which was isolated from the alpha-crystallin fraction of human lenses. METHODS: An inactive, Arg-bond hydrolyzing proteinase in the alpha-crystallin fraction, which was isolated from the water soluble (WS) protein fraction of 60- to 70-year-old human lenses, was activated by sodium deoxycholate treatment.
Our recent study has shown that betaA3-crystallin along with betaB1- and betaB2-crystallins were part of high molecular weight complex obtained from young, old, and cataractous lenses suggesting potential interactions between alpha- and beta-crystallins (Srivastava, O. P., Srivastava, K., and Chaves, J. M. (2008) Mol. Vis. 14, 1872-1885). To investigate this further, this study was carried out to determine the interaction sites of betaA3-crystallin with alphaA- and alphaB-crystallins.
The purpose of the study was to determine the effects of truncation of various regions of betaB1-crystallin on its structural properties and stability of heterooligomers formed by wild-type (WT) betaB1 or its deletion mutants with WT betaA3-crystallin.