Patent ID: 8666680

Claim:
A method of identifying an inhibitor of an Fcγ receptor molecule which lacks any of (i) a transmembrane domain, (ii) signal peptide and (iii) glycosylation, comprising the steps of: (a) obtaining a hexagonal crystal of a complex of an FcγRIII receptor molecule and hFc1, wherein the FcγRIII receptor molecule consists of SEQ ID NO:4, the immunoglobulin is hFc1, and the complex is FcγRIII:hFc1, wherein the crystal is in space group P6 5 22, with unit cell dimensions of about a=b=115.0 Å, c=303.3 Å, a=b=90° and γ=120°; (b) determining the three-dimensional structure of said complex using the crystal of (a) by the X-ray diffraction method; (c) displaying the three dimensional structure of said complex on a performing computer by inputting said crystal structure data of said complex, wherein the performing computer comprises a computer program to generate said three dimensional structure and to identify an inhibitor; and (d) selecting an inhibitor complementary to FcγRIII receptor binding site of an immunoglobulin molecule.