RESUMO
Objective:To construct an in vitro reconstitution system for inverse autotransporters in order to further investigate their translocation mechanism. Methods:Intimin from Escherichi coli was used as a model substrate. Spheroplasts were prepared from Escherichi coli strains overexpressing Intimin to induce the expression of Intimin. Recombinant β-barrel assembly machinery (BAM) complex was obtained and purified, and then proteoliposomes containing BAM were prepared. Following the digestion with proteinase K, the translocation was detected by SDS-PAGE. Results:Spheroplasts were induced to express Intimin, and then BAM-containing proteoliposomes were added to the system. Compared with control and liposomes groups, the experimental group showed that Intimin was resistant to proteinase K treatment, indicating that Intimin was successfully translocated.Conclusions:The translocation of Intimin required the participation of BAM complex. An in vitro reconstitution system for inverse autotransporters was constructed in this study, providing a method to study the translocation mechanism of inverse autotransporters.