A-B Pull-down assay. Input ligands-rhAng1 (A) and VT (B)-were incubated with either protein A sepharose beads only, bead-conjugated mouse Tie2-Fc (mTie2), or bead-conjugated human Tie2-Fc (hTie2). The 'bound' fraction shows the total amount pulled down by beads. The 'unbound' fraction is 7% of residual/free ligands remaining in the supernatant. 