Mechanical properties of the P-selectin/PSGL-1 interaction

Using an Atomic Force Microscope (AFM), the mechanical properties of the P-selectin/PSGL-1 complex were studied with two separate methods. Both methods yielded similar results. The molecular complex displayed a linear relationship between force and molecular extension. The dimeric bond of the wild type PSGL-1 interaction resulted in a spring constant roughly double that of a recombinant monomeric PSGL-1 interaction, suggesting that the two subunits of the dimeric interaction act as springs in parallel. The P-selectin portion of the complex was found to contribute the most to the mechanical compliance of the molecular complex.