E-selectin engagement of sLexon L-selectin requires cross-linking to induce phospho-Lck. (A) E-selectin or P-selectin cross-linked by the addition of polyclonal secondary antibody were immunoprecipitated in the absence and presence of glycomimetics. Western blot was applied to detect Lck along with its tyrosine phosphorylated state. (B) Activation of phospho-Lck was normalized to total protein to quantify the increase after E-selectin or P-selectin cross-linking in the presence of Rivipansel (6.5 μM) or GSnP-6 (12 μM). No significant increase was quantified for cross-linked P-selectin. Data presented as mean ± SEM for cross-linked E-selectin were significant compared with E-selectin alone (n = 3 separate experiments; **P < .01; ***P < .001).
