Fig. 4. (A,B) Filamin binding to blotted proteins. Duplicate loadings were used (A) for total protein detection with Coomassie blue and (B) for immunoblot detection of bound filamin. Lanes were loaded with purified proteins as indicated. The histidine-tagged CAT proteins (HIS-CAT-1, HIS-CAT-2) served as negative controls. Significant filamin binding to recombinant N-RAP-SR was observed. (C,D) Filamin binding to N-RAP recombinant proteins immobilized on Ni-NTA agarose beads. Duplicate loadings were used (C) for total protein detection with Coomassie blue and (D) for detection of bound filamin. Significant filamin binding to recombinant N-RAP-SR was observed.