Heat Shock Protein (hsp) Fragment

The small mammalian heat shock proteins show a highly conserved amino acid sequence and are suggested to play a major role in the increased thermal resistance acquired by cells after exposure to heat shock. They possess two major sites of phosphorylation which are each located in the conserved protein kinase phosphorylation site motif Arg-X-X-Ser. The above-mentioned phosphopeptide, which contains the second site of phosphorylation, has been isolated from a tryptic digest of phosphorylated native and recombinant mouse hsp 25. Only Ser??, the first of the three serine residues, is phosphorylated