Figure 4.

Conformational dependence of RTX aggregation. (A) Ca²⁺-bound RTX protein was evaluated by ThT binding kinetically, and free Ca²⁺ was chelated by addition of EGTA. Points of EGTA addition are labeled and indicated by arrowheads. (B) The stability of the ThT-bound, Ca²⁺-free species was assessed by addition of Ca²⁺. The vertical gray bar marks the addition of Ca²⁺ (red data set) or EGTA (blue data set). Data for native RTX protein in 2 mM Ca²⁺ (black data set) are shown as a control.