FIG. 1.

Binding of AAT to rEspB in a pull-down assay. rEspB was incubated with purified AAT, HeLa, or Caco-2 cell lysate. Pull-down experiments were performed as described in Materials and Methods. AAT was detected using anti-AAT antiserum. rEspB precipitates purified AAT (lane 1) and also AAT from HeLa (lane 3) and Caco-2 (lane 4) cell lysate. However, AAT was not detected when HeLa cell lysate was incubated with Ni-NTA-agarose matrix alone (lane 2). Molecular masses of standard proteins are indicated in kilodaltons (lane M).