HYDROPHOBIC PROBE 4,4'-BIS(1-ANILINO-8-NAPHTHALENE SULFONIC-ACID) IS SPECIFICALLY PHOTOINCORPORATED INTO THE N-TERMINAL DOMAIN OF ALPHA-B-CRYSTALLIN

Photoincorporation of the fluorescent probe 4,4'bis(1-anilino-8-naphth alene sulfonic acid) (bis-ANS) can be used to locate solvent-exposed h ydrophobic regions in proteins. We show that bis-ANS is specifically i ncorporated into the putative N-terminal domain of alpha B-crystallin. This incorporation diminishes the chaperone-like activity of alpha B- crystallin, suggesting that hydrophobic surfaces in the N-terminal dom ain are involved in the binding of unfolding proteins. (C) 1997 Federa tion of European Biochemical Societies.