FIG. 1.

Binding of HBMEC proteins to OmpA⁺ E. coli. Confluent monolayers of HBMEC were biotinylated, and membrane proteins were prepared and incubated with OmpA⁺ and OmpA⁻ E. coli strains as described in Materials and Methods. Biotinylated BSA was used as a control. In some experiments, the HBMEC membrane proteins were preincubated with either outer membrane proteins of E44 (OmpA-Lipo.) or E91 (E91-Lipo.) reconstituted in liposomes for 30 min on ice, followed by incubation with E44. Similarly biotinylated HUVEC and CEC membranes were also analyzed by immunoblotting with streptavidin-peroxidase for their binding capacity to E44. The bound proteins were identified by diaminobenzidene and hydrogen peroxide. The molecular weight markers are indicated on the right.