FIGURE 4.

Analysis of oligomeric states of MBP-4A-S1R by chemical cross-linking agent DSS. DSS-free controls are shown by lanes 1 and 2, containing 0 and 10 μm high affinity ligand BD-1047, respectively. Lanes 3 and 4 mirror the control with the addition of DSS. A, addition of cross-linking agent to the monomer (Fig. 2A, peak 2). The bands show slight smearing with no shift in size, signifying only intramolecular cross-linking. B, addition of cross-linking agent to the oligomer (Fig. 2A, peak 1). The bands show a mass greater than 300 kDa, and oligomeric stoichiometry cannot be accurately determined. However, an oligomeric state greater than tetramer is clearly visible. C, addition of cross-linking agent to the intermediate oligomer (Fig. 2A, peak *). The bands show an approximate 4-fold increase in size to a mass between 250 and 300 kDa, suggesting a tetrameric state.