Characterizing L-selectin/PSGL-1 interactions using an atomic force microscope

The kinetic and mechanical properties of L-selectin interacting with monomeric and dimeric P-selectin glycoprotein ligand-1 (PSGL-1) were characterized using an atomic force microscope (AFM). A majority of the results were qualitatively similar to but quantitatively different from those of P-selectin/PSGL-1 interactions previously obtained, consistent with the structural and functional similarity of the two selectins. One exception was that differences that occurred when the two forms of PSGL-1 were tested against P-selectin were no longer observed in the case of L-selectin. This suggests that L-selectin does not support dimeric interactions with dimeric PSGL-1 under the conditions tested.