Patent ID: 7888050

Claim:
A method for quantitatively measuring kinase activity of a kinase comprising: (a) contacting a protein with the kinase to phosphorylate a phosphorylation site on the protein; (b) capturing the protein with a first pan antibody that binds both a phosphorylated and non-phosphorylated form of the protein to form a captured protein; (c) contacting the captured protein with a phosphorylation site-specific antibody (PSSA) wherein the PSSA binds to the phosphorylated phosphorylation site on the protein to form a bound phosphorylated protein; (d) contacting the captured protein with a second pan antibody that binds both the phosphorylated and non-phosphorylated form of the protein, wherein the second pan antibody recognizes an epitope on the protein that is not recognized by the first pan antibody to form a bound total captured protein; (e) detecting the PSSA bound to the phosphorylated protein; and (f) detecting the second pan antibody bound to the total captured protein, to determine the fraction of the protein that is phosphorylated at the phosphorylation site, thereby quantitatively measuring the kinase activity of the kinase.