The native peptide, RRGRTGRGRRGIFR (cat# 60542-1), is proven to be a highly selective substrate for Protein Kinase C (PKC). It is based on the amino acid sequence 1487-1500 of the non-structural protein 3 of Hepatitis C virus (HCV). Substitution of Tyr1499 in HCV by Phe makes the peptide substrate more effectively phosphorylated by rat brain PKC (Km = 5 µM) and mouse epidermal cell extracts (Km = 25 nM) than other kinases such as tyrosine kinases or other serine/threonine kinases. It is very useful for assaying PKC activity in the presence of other kinases in tissues and crude cell extracts.
Ref: Borowski, P. et al. J. Biol. Chem. 274, 30722 (1999).