FIGURE 1.

Characterization of the purified CXCR4. A, purified CXCR4 was loaded on a 12% SDS-polyacrylamide gel. The gel was stained with Coomassie Brilliant Blue. B, normalized SPR responses for FLAG-M5 binding to N-terminally FLAG-tagged CXCR4 (dotted line) and 12G5 binding to CXCR4 (solid line). C, SDF-1 binding activity of the purified CXCR4 analyzed by a pulldown assay. Each fraction was loaded on a 15% SDS-polyacrylamide gel, which was silver-stained. D, normalized SPR responses for 12G5 binding to CXCR4, incubated under various conditions. B and D, the entire sensorgrams were divided by the CXCR4 capture levels (RU_CXCR4). RU, resonance units; MAb, monoclonal antibody.