Patent ID: 7892775

Claim:
A method for detecting kinase activity, comprising the steps of: (a) providing a peptide comprising: (1) a kinase recognition sequence containing a phosphorylation site; (2) a β-turn sequence; and (3) an amino acid of the formula (I): where each R is independently hydrogen or —SO 2 X, wherein at least one R group is —SO 2 X, where X is —OR″ or —NR″R′″; R′ is hydroxy, amino, or thiol; R″ is C 1-6 alkyl; R′″ is hydrogen or alkyl; and n is 1, 2 or 3; (b) contacting the peptide with a sample comprising Mg 2+ , a phosphate source, and a kinase; and (c) analyzing for the presence of a phosphorylated peptide product.