Phosphorylation

H-Tyr(PO3H2)-Val-Asn-Val-OH                                         1 mg $ 220
                                                                                           5 mg $ 800

This peptide corresponds to residues 317 to 320 of the oncogenic protein Shc. Similar phosphotyrosine motifs are also found in receptor tyrosine kinases and substrates of them. This peptide binds with high affinity (18 nM) to the SH2 domain of the growth factor bound-2 protein (Grb2). It is a useful inhibitor of the interaction of Grb2 with Shc, or with other Grb-2-binding proteins involved in the cell signaling cascade.

H-Cys-Leu-Asn-Arg-Gln-Leu-Ser(PO3H2)-Ser-Gly-Val-Ser-Glu-Ile-Arg-OH   
                                                                                                 1 mg $ 305 
                                                                                                 5 mg $ 1220
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 Ser86, the first of the three serine residues is phosphorylated