Preferentially recognizes peptides and proteins containing phospho-Ser/Thr preceded by Lys/Arg at positions -5 and -3, in a manner largely independent of other surrounding amino acids. Some cross-reactivity is observed for peptides that contain phospho-Ser/Thr preceded by Arg/Lys at positions -3 and -2. No cross-reactivity is observed with the corresponding non-phosphorylated sequences or with other phospho-Ser/Thr-containing motifs. By ELISA the antibody recognizes a wide range of phosphorylated Akt substrate peptides and by 2D gel Western blot analysis it recognizes a large number of presumptive Akt substrate proteins.