FIGURE 2.

SP blocked homophilic Dsg3 or Dsg1 transinteraction and TP prevented PV-IgG- and AK 23-induced blocking of Dsg3 transinteraction in cell-free AFM studies. Binding activities of Dsg3 (black bars) and Dsg1 (white bars) fusion proteins coupled to the tip and plate of the AFM setup were strongly reduced after Ca²⁺ depletion. SP (200 μm) also blocked Dsg3 and Dsg1 transinteraction, whereas TP (20 μm) and the corresponding control peptides CP-1 and CP-2 did not. PV-IgG 1 and PV-IgG 2 interfered with Dsg3 transinteraction. Preincubation with TP (20 μm, p = 0.00360 and p = 0.00036, respectively) but not CP-2 (20 μm, p = 0.4139) prevented PV-IgG 1- and PV-IgG 2-induced loss of Dsg3 adhesion. Similar results were obtained with mouse PV antibody AK 23 (p = 0.00275). PV-IgG 1 did not directly inhibit homophilic Dsg1 transinteraction (n = 3–4 for each condition).