Disruption of PF4 tetramers. (A) Cartoon based on the crystal structure of PF4, illustrating the salt bridges that may be important in tetramer formation. (B) SDS-PAGE demonstrating the equilibrium of PF4 monomer (M), dimers (D), and tetramers (T) in WT PF4 and PF4 with induced mutations after BS3 crosslinking. This gel is representative of 3 independent experiments. (C-D) Chromatographs from SEC-HPLC of PF4-K50E (C) and PF4-E28R-K50E (D), as in Figure 1.