Average rate of pore closure after adding inhibitors of 6HB formation. The fluorescence (A) and pore permeability (B) after the addition (indicated by downward arrow) at 4°C of the inhibitory peptides C34 (47 nM, ○, n = 5) or N36 (4 μM, ▵, n = 7) or, as a control, BSA (▪, n = 8), as averaged from multiple experiments. In the control experiments, we changed the external solution by the same procedure used to add peptides, to ensure that the peptides themselves were causing the inhibitory effect, rather than a simple shear stress on the E/T cell pairs. (A) Fluorescence traces from individual experiments were aligned at the time of peptide addition, and the average fluorescence from multiple experiments over the next 200 s was calculated. Bars, SEs of mean. (B) Pore permeabilities, calculated from the averaged fluorescence intensities (traces in A). The addition of C34 or N36, but not BSA, caused pore closure.