Comparison of the homologous carboxy-terminal domain and tail of α-crystallin and small heat shock protein

Abstract

The C-terminal domain and tail, which is the most conserved region of the α-crystallin/small heat shock protein (HSP) family, was obtained from rat αA-crystallin, bovine αB-crystallin and mouse HSP25. All three domains have primarily β-sheet conformation and less than 10% of α-helix, like the proteins from which they are derived. Whereas the C-terminal part of αA-crystallin forms dimers or tetramers, the corresponding regions of αB-crystallin and HSP25 form larger aggregates. The heat-protective activity, recently described for the α-crystallin/small HSP family, is not retained in the C-terminal domain and tail. In the course of this study some differences with the previously published sequence of HSP25 were observed, and a revision is proposed.