scholarly journals Binding Sites of Outer Membrane Protein A (OmpA) in the Complex with the Periplasmic Chaperone Skp from E. Coli. A site-directed fluorescence study

2009 ◽  
Vol 96 (3) ◽  
pp. 449a-450a ◽  
Author(s):  
Jian Qu ◽  
Susanne Behrens ◽  
Otto Holst ◽  
Jörg H. Kleinschmidt
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Binding Sites ◽  
Protein A ◽  
Fluorescence Study ◽  
E Coli ◽  
Periplasmic Chaperone ◽  
Outer Membrane Protein A ◽  
A Site

scholarly journals Cloning and Expression of the Escherichia coli K1 Outer Membrane Protein A Receptor, a gp96 Homologue

2003 ◽  
Vol 71 (4) ◽  
pp. 1680-1688 ◽  
Author(s):  
Nemani V. Prasadarao ◽  
Pramod K. Srivastava ◽  
Rajyalakshmi S. Rudrabhatla ◽  
Kwang Sik Kim ◽  
Sheng-he Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein A ◽  
Tumor Rejection ◽  
Cloning And Expression ◽  
Cdna Expression Library ◽  
E Coli ◽  
Outer Membrane Protein A

ABSTRACT Escherichia coli is one of the most common gram-negative bacteria that cause meningitis in neonates. Our previous studies have shown that outer membrane protein A (OmpA) of E. coli interacts with a 95-kDa human brain microvascular endothelial cell (HBMEC) glycoprotein, Ecgp, for invasion. Here, we report the identification of a gene that encodes Ecgp by screening of an HBMEC cDNA expression library as well as by 5′ rapid amplification of cDNA ends. The sequence of the Ecgp gene shows that it is highly similar to gp96, a tumor rejection antigen-1, and contains an endoplasmic reticulum retention signal, KDEL. Overexpression of either Ecgp or gp96 in both HBMECs and CHO cells increases E. coli binding and invasion. We further show that Ecgp gene-transfected HBMECs express Ecgp on the cell surface despite the presence of the KDEL motif. Northern blot analysis of total RNA from various eukaryotic cells indicates that Ecgp is significantly expressed in HBMECs. Recombinant His-tagged Ecgp blocked E. coli invasion efficiently by binding directly to the bacteria. These results suggest that OmpA of E. coli K1 interacts with a gp96-like molecule on HBMECs for invasion.

scholarly journals Immunoprotective evaluation of Escherichia coli outer membrane protein A against the main pathogens of animal mastitis

2020 ◽  
Vol 19 (1) ◽  
pp. 155-162
Author(s):  
Chen Chen ◽  
Nana Wu ◽  
Na Rong ◽  
Chao Kang ◽  
Chunlin Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Function ◽  
E Coli ◽  
Ompa Protein ◽  
Outer Membrane Protein A

Purpose: To evaluate prokaryotic expression of the Escherichia coli (E. coli) outer membrane protein A (OmpA) and its immunoprotective function against the main pathogens of animal mastitis.Methods: A molecular cloning method was used to develop a prokaryotic strain expressing OmpA protein, which was purified by Ni-affinity  chromatography. Polyclonal antiserum was generated in mice immunized with OmpA protein. Enzyme-linked immunosorbent assay (ELISA) and western blotting were used to determine the titer and verify anti-OmpA serum specificity, respectively. Interaction between OmpA antiserum and main pathogens of animal mastitis was verified by ELISA and a pull-down method. The immune protective function of OmpA protein was evaluated in mice challenged with pathogens of animal mastitis. Optimal fermentation conditions to produce OmpA protein were determined by the L9(34) orthogonal test.Results: A prokaryotic strain expressing OmpA protein was developed, and purified OmpA was used to develop a mouse polyclonal antibody. The anti-OmpA serum exhibited high specificity and a titer of 1:1600. Anti-OmpA serum directly interacted with E. coli and Staphylococcus aureus (S. aureus). OmpA demonstrated a significant immune protective function of 58.33 % against E. coli and 46.15 % against S. aureus. The optimal conditions for expressing fermentation OmpA were a strain absorbance of 0.5 at a wavelength of 600 nm, IPTG final concentration of 0.3 mmol/L, induction time of 12 h, and induction temperature of 28 °C.Conclusion: OmpA possesses selective immunogenicity and a significant immune protective effect against the main pathogens of animal mastitis. The results suggest that OmpA may potentially be used as a vaccine for animal mastitis. Keywords: E. coli, OmpA protein, Immunoprotection, Animal mastitis, Protein fermentation

scholarly journals Entry and Intracellular Replication of Escherichia coli K1 in Macrophages Require Expression of Outer Membrane Protein A

2003 ◽  
Vol 71 (10) ◽  
pp. 5951-5961 ◽  
Author(s):  
Sunil K. Sukumaran ◽  
Hiroyuki Shimada ◽  
Nemani V. Prasadarao
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Human Peripheral Blood ◽  
Protein A ◽  
Raw 264.7 Cells ◽  
Human Macrophage ◽  
E Coli ◽  
Outer Membrane Protein A

ABSTRACT Interactions between Escherichia coli K1, which causes meningitis in neonates, and macrophages have not been explored well. In this study we found that E. coli K1 was able to enter, survive, and replicate intracellularly in both murine and human macrophage cell lines, as well as in monocytes and macrophages of newborn rats. In addition, we demonstrated that OmpA + E. coli also enters and replicates in human peripheral blood monocytes in vitro. Outer membrane protein A (OmpA) expression on E. coli contributes to binding to macrophages, phagocytosis, and survival within macrophages. Opsonization with either complement proteins or antibody is not required for uptake and survival of the bacteria within the macrophages. Transmission electron microscopy and immunocytochemistry studies with the infected macrophages indicated that OmpA+ E. coli multiplies enormously in a single phagosome and bursts the cell. Internalization of OmpA+ E. coli by RAW 264.7 cells occurred by both actin- and microtubule-dependent processes, which are independent of RGD-mediated integrin receptors. Internalization and intracellular survival within phagocytic cells thus may play an important role in the development of bacteremia, which is crucial for E. coli crossing of the blood-brain barrier.

Overexpression of Outer Membrane Protein A Is a Risk Factor for Mortality in Escherichia coli Bloodstream Infections

2019 ◽  
Author(s):  
Ángel Rodríguez-Villodres ◽  
Rocío Álvarez-Marín ◽  
María Antonia Pérez-Moreno ◽  
Andrea Miró-Canturri ◽  
Marco Durán Lobato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Risk Factor ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein A ◽  
Bloodstream Infections ◽  
Outer Membrane Protein A

scholarly journals Anaplasma phagocytophilum Outer Membrane Protein A Interacts with Sialylated Glycoproteins To Promote Infection of Mammalian Host Cells

2012 ◽  
Vol 80 (11) ◽  
pp. 3748-3760 ◽  
Author(s):  
Nore Ojogun ◽  
Amandeep Kahlon ◽  
Stephanie A. Ragland ◽  
Matthew J. Troese ◽  
Juliana E. Mastronunzio ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Anaplasma Phagocytophilum ◽  
Protein A ◽  
Host Cells ◽  
Mammalian Host ◽  
Content Type ◽  
Outer Membrane Protein A ◽  
Sialylated Glycoproteins

ABSTRACTAnaplasma phagocytophilumis the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis (HGA).A. phagocytophilumbinding to sialyl Lewis x (sLex) and other sialylated glycans that decorate P selectin glycoprotein 1 (PSGL-1) and other glycoproteins is critical for infection of mammalian host cells. Here, we demonstrate the importance ofA. phagocytophilumouter membrane protein A (OmpA) APH_0338 in infection of mammalian host cells. OmpA is transcriptionally induced during transmission feeding ofA. phagocytophilum-infected ticks on mice and is upregulated during invasion of HL-60 cells. OmpA is presented on the pathogen's surface. Sera from HGA patients and experimentally infected mice recognize recombinant OmpA. Pretreatment ofA. phagocytophilumorganisms with OmpA antiserum reduces their abilities to infect HL-60 cells. The OmpA N-terminal region is predicted to contain the protein's extracellular domain. GlutathioneS-transferase (GST)-tagged versions of OmpA and OmpA amino acids 19 to 74 (OmpA19-74) but not OmpA75-205bind to, and competitively inhibitA. phagocytophiluminfection of, host cells. Pretreatment of host cells with sialidase or trypsin reduces or nearly eliminates, respectively, GST-OmpA adhesion. Therefore, OmpA interacts with sialylated glycoproteins. This study identifies the firstA. phagocytophilumadhesin-receptor pair and delineates the region of OmpA that is critical for infection.

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