Previously we discovered that OmpA of Escherichia coli increases biofilm formation on polystyrene surfaces (González Barrios et al., Biotechnol Bioeng, 93:188-200, 2006a). Here we show OmpA influences biofilm formation differently on hydrophobic and hydrophilic surfaces since it represses cellulose production which is hydrophilic. OmpA increased biofilm formation on polystyrene, polypropylene, ...

Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-terminal domain contains eight βbarrel regions that plays important roles in the multifaceted functions of OmpA. In the present study, we cloned a mutant OmpA gene from a multi-antibi...

The ompA gene, encoding the 42-kDa major antigenic outer membrane protein OmpA of Riemerella anatipestifer, the etiololgical agent of septicemia anserum exsudativa, was cloned and expressed in Escherichia coli. Recombinant OmpA displayed a molecular mass similar to that predicted from the nucleotide sequence of the ompA gene but lower than that observed in total cell lysates of R. anatipestifer...

The bacterial outer membrane protein OmpA is one of the few membrane proteins whose structure has been solved both by X-ray crystallography and by NMR. Crystals were obtained in the presence of detergent, and the NMR structure is of the protein in a detergent micelle. We have used 10 ns duration molecular dynamics simulations to compare the behaviour of OmpA in a detergent micelle and in a phos...

Outer membrane protein A (OmpA), a major structural protein of the outer membrane of Escherichia coli, consists of an N-terminal 8-stranded beta-barrel transmembrane domain and a C-terminal periplasmic domain. OmpA has served as an excellent model for studying the mechanism of insertion, folding, and assembly of constitutive integral membrane proteins in vivo and in vitro. The function of OmpA ...

B cells are critically important in combating bacterial infections and their differentiation into plasma cells and memory cells aids bacterial clearance and long-lasting immunity conferred by essentially all vaccines. Outer membrane protein A (OmpA) of Shigella flexneri 2a has been demonstrated to induce the production of IgG and IgA in vivo following immunization of mice through intranasal rou...

DNA sequences coding for 81% of the ompA gene from 24 chlamydial strains, representing all chlamydial species, were determined from DNA amplified by polymerase chain reactions. Chlamydial strains of serovars and strains with similar chromosomal restriction fragment length polymorphism had identical ompA DNA sequences. The ompA sequences were segregated into 23 different ompA alleles and aligned...

We determine that OmpA of Shigella flexneri 2a is recognized by TLR2 and consequently mediates the release of proinflammatory cytokines and activates NF-κB in HEK 293 cells transfected with TLR2. We also observe that in RAW macrophages TLR2 is essential to instigate the early immune response to OmpA via NF-κB activation and secretion of cytokines and NO. Consistent with these results, TLR2 knoc...

Fc-fusion technologies, in which immunoglobulin Fc is genetically fused to an antigenic protein, have been developed to confer antibody-like properties to proteins and peptides. Mammalian IgG Fc fusion exhibits improved antigen-induced immune responses by providing aggregates with high avidity for the IgG Fc receptor and salvaging the antigenic portion from endosomal degradation. However, wheth...

The current topological model for the Escherichia coli outer membrane protein OmpA predicts eight N-terminal transmembrane segments followed by a long periplasmic tail. Several recent reports have raised serious doubts about the accuracy of this prediction. An alternative OmpA model has been constructed using (1) computer-aided predictions developed specifically to predict topology of bacterial...