Effect of binding valence on bond lifetime. (A) Receptor and/or ligand multimericity or clustering does not affect bond lifetime between OT1 TCR (either recombinant or native) and OVA:H2-Kbα3A2. For the recombinant OT1 TCR, tetrameric and monomeric binding was measured, respectively, using tetravalent and monovalent streptavidin (SA) to capture both the TCR and the pMHC. For the native OT1 TCR, only valence of pMHC was manipulated using tetravalent and monovalent SA coupling, respectively. Divalent L-selectin was used as a control. p-Values were indicated for interactions between tetrameric and monomeric receptor(s) and ligand(s). Data are shown as mean + SEM of >50 lifetime events and are pooled from one to five independent experiments. (B–F) Lifetime distributions corresponding to panel (A).