PKA inhibitor fragment (6-22) amide is a synthetic peptide inhibitor of cAMP-dependent protein kinase (PKA; Ki = 1.7 nM) derived from the heat-stable PKA inhibitor protein PKI. It is the shortest synthetic PKI peptide that retains high potency for PKA inhibition. Both the arginine-containing pseudosubstrate site of the PKI peptide in its COOH terminus and the residue Phe10 in NH2-terminal portion are required for this high affinity binding.
