Fig. 5.

RBS-specific soluble ligands induce H tetramer reorganization. (A) Exposure of H-expressing cells to sSLAM before digitonin extraction and native-PAGE analysis returns H tetramer/sSLAM complexes of similar mobility (arrowheads). (B) Exposure of H-expressing cells to RBS-specific mAb E128 (competes with CD46 receptor binding) or nonneutralizing H-specific mAbs CV1 CV4. Although all E128/H tetramer complexes show indistinguishable migration profiles (white arrowheads), CV1 CV4/H-F111A tetramers retain distinct electrophoretic mobility (black arrowheads). (C) Consecutive exposure of H tetramers to heat and RBS-specific ligands. H material was extracted with digitonin and was kept at 4 °C (4) or was heated to 60 °C (60) for 10 min. Subsequently, samples were exposed to RBS-specific ligand (E128, sSLAM) or vehicle (mock).