FIG. 2.

Interaction of proHlyA and HlyA with liposomes. (A) Purified proHlyA and HlyA were incubated without (−PLV) or with (+ PLV) phospholipid vesicles in the presence (+ Ca²⁺) or absence (+ EGTA) of Ca²⁺ and analyzed by centrifugation (flotation) through a sucrose gradient. Top (T) and bottom (B) fractions were analyzed by SDS-10% PAGE and Coomassie staining. (B) Insertion-dependent labeling. ProHlyA, HlyA, S. aureus α-hemolysin (S.a.Hly) as a positive control and ovalbumin as a negative control were incubated (2 μg of each) with liposomes in which [¹²⁵I]TID was incorporated. Ca²⁺ was present (+) or absent (−). Samples were analyzed by SDS-10% PAGE and developed by Coomassie staining (i) and phosphorimage detection (ii).