Patent ID: 7105305

Claim:
A method of selecting a molecule capable of inhibiting binding of a PI3 kinase protein which binds to a PDGF receptor polypeptide, the method comprising the steps of: contacting the PI3 kinase protein with the PDGF receptor polypeptide in the presence of a test molecule in a first step; contacting the PI3 kinase protein with the PDGF receptor polypeptide in the absence of the test molecule in a second step; wherein the PDGF receptor polypeptide is selected from the group consisting of i) a polypeptide consisting of amino acids beginning at 695 and ending at 798 of a B type hPDGF-R, as shown in SEQ ID NO: 4, ii) a polypeptide consisting of amino acids beginning at 604 and ending at 951 of a B type hPDGF-R, as shown in SEQ ID NO: 4, iii) a polypeptide consisting of amino acids beginning at 695 and ending at 951 of a B type hPDGF-R, as shown in SEQ ID NO: 4, and iv) a polypeptide consisting of amino acids beginning at 557 and ending at 951 of a B type hPDGF-R, as shown in SEQ ID NO: 4; wherein the polypeptide is phosphorylated at Tyr 751 or at Tyr 740; and comparing the amount of PDGF receptor binding to PI3 kinase in the first and second steps, wherein a lower level of binding detected in the first step is an indication that the test molecule is capable of inhibiting binding of PI3 kinase to PDGF receptor polypeptide, thereby selecting a molecule capable of inhibiting binding of a PI3 kinase protein to a PDGF receptor polypeptide.