Patent ID: 7727752

Claim:
A method for identifying a modulator of activity of a kinase, comprising: a) forming a kinase mixture comprising a protein kinase, a composition, and a test compound; b) contacting the kinase mixture with a protease to form a protease mixture; c) forming a control mixture comprising the protein kinase, the composition, and the protease; and d) comparing a measurable property in the protease mixture to the measurable property in the control mixture, wherein the test compound is identified as a modulator of activity of the kinase if the measurable property in the protease mixture is different from the measurable property in the control mixture, and wherein the composition comprises: (i) a peptide having a length from five to fifty amino acids, the peptide comprising a motif, wherein the motif is: TX 1 YVA, where X 1 can be G, A, or E (SEQ ID NO: 10); (ii) a first detectable moiety, wherein the first detectable moiety is associated with the peptide; and (iii) a protease cleavage site, wherein the protease cleavage site is located in a position relative to the motif such that enzymatic modification of the motif alters the proteolytic cleavage of the peptide; wherein the protein kinase is selected from the group consisting of CSF 1 R,FLT 3 , and c-Kit.