|(11)||EP 2 267 033 A3|
|(12)||EUROPEAN PATENT APPLICATION|
|(54)||Gold-binding protein and use thereof|
|(57) A target substance capturing body comprises a substrate and a protein set on the surface of the substrate. The surface of the substrate comprises a portion formed of gold, and the protein comprises a first domain and a second domain. The first domain comprises at least an antibody heavy chain variable region (VH) or an antibody light chain variable region (VL), wherein the antibody heavy chain variable region (VH) or the antibody light chain variable region (VL) comprises a region specifically binding to gold of the substrate at KD = 3.0 × 10-7 M or less. Further, the second domain comprises a region specifically binding to a target substance. The protein is set on the substrate in a form that the region of the first domain specifically binding to gold binds to the portion formed of gold of the surface of the substrate.