H-1-NMR SPECTROSCOPY REVEALS THAT MOUSE HSP25 HAS A FLEXIBLE C-TERMINAL EXTENSION OF 18 AMINO-ACIDS

The small heat-shock proteins (Hsps) exist as large and stabilising no n-native proteins in a chaperone-like manner. Two-dimensional H-1 NMR spectroscopy of mouse Hsp25 reveals that the last 18 amino acids have great flexibility with motion that is essentially independent of the d omain care of the protein. The lens protein, alpha-crystallin, is homo logous to Hsp25 and its two subunits also have flexible C-terminal ext ensions. The flexible region in Hsp25 encompasses exactly that expecte d from sequence comparison with alpha-crystallin implying that both pr oteins have similar structures and that the C-terminal extensions coul d be of functional importance for both proteins.