Figure 6. Bound TEA precludes K⁺ from accessing S₄ binding site, but bound RY785 allows it.

(A) Five independent simulations of Kv2.1 bound to TEA wherein a knock-on event was artificially induced in the selectivity filter at t = 100 ns, to create a K⁺ vacancy in site S₄. K⁺ did not reload this site in the subsequent 100 ns, except when TEA spontaneously dissociated prior to the knock-on event (right). (B) Same as (A), for Kv2.1 bound to RY785. In all simulations, a K⁺ ion reloads the S₄ site within ~10 ns of the induced knock-on event, corroborating RY785 is not an open-state blocker of Kv2.1.