The natural peptide AAKIQASFRGHMARKK (27173) is a synthetic PKC substrate derived from the naturally occurring PKC substrate neurogranin sequence. The peptide is a very specific PKC substrate. It is phosphorylated by purified PKC with a Km of 150nm. Neither PKA nor camk2 reported the phosphorylation of this peptide. Substituting Ile for Arg36 will significantly reduce the affinity of PKC. Substituting arginine for Lys30 can increase the catalytic efficiency of PKC (Vmax/Km), but reduces the substrate selectivity for PKC. It is generally believed that the basic amino acids on both sides of phosphorylated serine are important structural determinants of PKC substrates. In addition, the presence of specific basic amino acids (arginine vs lysine) may also affect the degree of substrate selectivity for PKC.
Ref: Chang, DK. et al. Biophys. J. 72, 554 (1997); Chen, SJ. et al. Biochem. 32, 1032 (1993).
Sequence (One-Letter Code)
Sequence (Three-Letter Code)
Biotin - LC - Ala - Ala - Lys - Ile - Gln - Ala - Ser - Phe - Arg - Gly - His - Met - Ala - Arg - Lys - Lys - OH