Figure 4.

Static and dynamic simulations are used to predict tight junction pore barrier. (A) In a static model, each tight junction strand has a low conductance (2 pS per 100 nm) and is populated by four 70 pS claudin pores per 100 nm of tight junction.¹⁷ (B) In a dynamic model, only a percentage of claudins form conductive pores, and pores randomly flicker between open and closed states with defined probabilities. The percentage of open pores is defined by the probability of a closed claudin moving to an open state and an open claudin moving to a closed state. (C) In a dynamic model (red), conductance is higher than would be predicted for a simple inverse relationship with strand number (as is true for the static model, green), and conductance may be quite sensitive to the percentage of open claudin-2 pores.