scholarly journals Effects of carbamate pesticides intermediates on Escherichia coli membrane architecture: An in vitro and in silico approach

2021 ◽  
Vol 36 (3) ◽  
pp. e2021020
Author(s):  
Pushpendra Singh ◽  
Manish Kumar Tripathi ◽  
Mohammad Yasir ◽  
Ashish Ranjan ◽  
Rahul Shrivastava
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
In Silico ◽  
Synthetic Analogue ◽  
Methyl Isocyanate ◽  
Kcal Mole ◽  
E Coli

Methyl isocyanate (MIC), a low molecular weight synthetic aliphatic compound, having an isocyanate group (−NCO), has industrial application. In this study, the effects of methyl isocyanate and its mechanism on outer membrane protein of Escherichia coli were observed using experimental and computational methods. In vitro exposure of N-succinimidyl N-methylcarbamate (NSNM) a synthetic analogue of MIC on E. coli to a final concentration of 2 mM was found to affect the growth curve pattern and changes in cell morphology. Molecular docking studies of MIC and NSNM with E. coli outer membrane protein (OmpW, OmpX, OmpF OmpA), and periplasmic domain (PAL) were performed. The in-silico results revealed that outer membrane protein OmpF showed the highest negative binding energy, i.e. ∆G -4.11 kcal/mole and ∆G -3.19 kcal/mole by NSNM and MIC as compared to other proteins. Our study concludes that methyl isocyanate retains lethal toxicity which leads to cell death due to the membrane protein damage of E. coli membrane.

scholarly journals NlpI Facilitates Deposition of C4bp on Escherichia coli by Blocking Classical Complement-Mediated Killing, Which Results in High-Level Bacteremia

2012 ◽  
Vol 80 (10) ◽  
pp. 3669-3678 ◽  
Author(s):  
Yu-ting Tseng ◽  
Shainn-Wei Wang ◽  
Kwang Sik Kim ◽  
Ying-Hsiang Wang ◽  
Yufeng Yao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Neonatal Meningitis ◽  
Content Type ◽  
E Coli ◽  
Classical Complement Pathway ◽  
High Level ◽  
Classical Complement

ABSTRACTNeonatal meningitisEscherichia coli(NMEC) is the most common Gram-negative organism that is associated with neonatal meningitis, which usually develops as a result of hematogenous spread of the bacteria. There are two key pathogenesis processes for NMEC to penetrate into the brain, the essential step for the development ofE. colimeningitis: a high-level bacteremia and traversal of the blood-brain barrier (BBB). Our previous study has shown that the bacterial outer membrane protein NlpI contributes to NMEC binding to and invasion of brain microvascular endothelial cells, the major component cells of the BBB, suggesting a role for NlpI in NMEC crossing of the BBB. In this study, we showed that NlpI is involved in inducing a high level of bacteremia. In addition, NlpI contributed to the recruitment of the complement regulator C4bp to the surface of NMEC to evade serum killing, which is mediated by the classical complement pathway. NlpI may be involved in the interaction between C4bp and OmpA, which is an outer membrane protein that directly interacts with C4bp on the bacterial surface. The involvement of NlpI in two key pathogenesis processes of NMEC meningitis may make this bacterial factor a potential target for prevention and therapy ofE. colimeningitis.

scholarly journals Coevolution of Bacteriophage PP01 and Escherichia coli O157:H7 in Continuous Culture

2003 ◽  
Vol 69 (1) ◽  
pp. 170-176 ◽  
Author(s):  
Katsunori Mizoguchi ◽  
Masatomo Morita ◽  
Curt R. Fischer ◽  
Masatoshi Yoichi ◽  
Yasunori Tanji ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Continuous Culture ◽  
Dilution Rate ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Escape Mutant ◽  
E Coli ◽  
Escape Mutants ◽  
Low Efficiency

ABSTRACT The interaction between Escherichia coli O157:H7 and its specific bacteriophage PP01 was investigated in chemostat continuous culture. Following the addition of bacteriophage PP01, E. coli O157:H7 cell lysis was observed by over 4 orders of magnitude at a dilution rate of 0.876 h−1 and by 3 orders of magnitude at a lower dilution rate (0.327 h−1). However, the appearance of a series of phage-resistant E. coli isolates, which showed a low efficiency of plating against bacteriophage PP01, led to an increase in the cell concentration in the culture. The colony shape, outer membrane protein expression, and lipopolysaccharide production of each escape mutant were compared. Cessation of major outer membrane protein OmpC production and alteration of lipopolysaccharide composition enabled E. coli O157:H7 to escape PP01 infection. One of the escape mutants of E. coli O157:H7 which formed a mucoid colony (Mu) on Luria-Bertani agar appeared 56 h postincubation at a dilution rate of 0.867 h−1 and persisted until the end of the experiment (∼200 h). Mu mutant cells could coexist with bacteriophage PP01 in batch culture. Concentrations of the Mu cells and bacteriophage PP01 increased together. The appearance of mutant phage, which showed a different host range among the O157:H7 escape mutants than wild-type PP01, was also detected in the chemostat culture. Thus, coevolution of phage and E. coli O157:H7 proceeded as a mutual arms race in chemostat continuous culture.

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 Refolding of Escherichia coli outer membrane protein F in detergent creates LPS-free trimers and asymmetric dimers

2005 ◽  
Vol 392 (2) ◽  
pp. 375-381 ◽  
Author(s):  
Virak Visudtiphole ◽  
Matthew B. Thomas ◽  
David A. Chalton ◽  
Jeremy H. Lakey
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Single Molecule ◽  
Outer Membrane Protein ◽  
Structural Integrity ◽  
Protein F ◽  
Outer Membrane Protein F

The Escherichia coli OmpF (outer-membrane protein F; matrix porin) is a homotrimeric β-barrel and a member of the bacterial porin superfamily. It is the best characterized porin protein, but has resisted attempts to refold it efficiently in vitro. In the present paper, we report the discovery of detergent-based folding conditions, including dodecylglucoside, which can create pure samples of trimeric OmpF. Whereas outer membrane LPS (lipopolysaccharide) is clearly required for in vivo folding, the artificially refolded and LPS-free trimer has properties identical with those of the outer-membrane-derived form. Thus LPS is not required either for in vitro folding or for structural integrity. Dimeric forms of OmpF have been observed in vivo and are proposed to be folding intermediates. In vitro, dimers occur transiently in refolding of trimeric OmpF and, in the presence of dodecylmaltoside, pure dimer can be prepared. This form has less β-structure by CD and shows lower thermal stability than the trimer. Study of these proteins at the single-molecule level is possible because each OmpF subunit forms a distinct ion channel. Whereas each trimer contains three channels of equal conductance, each dimer always contains two distinct channel sizes. This provides clear evidence that the two otherwise identical monomers adopt different structures in the dimer and indicates that the asymmetric interaction, characteristic of C3 symmetry, is formed at the dimer stage. This asymmetric dimer may be generally relevant to the folding of oligomeric proteins with odd numbers of subunits such as aspartate transcarbamoylase.

Isolation of FC3-11, a bacteriophage specific for theKlebsiella pneumoniaeporin OmpK36, and its use for the isolation of porin-deficient mutants

1995 ◽  
Vol 41 (4-5) ◽  
pp. 399-406 ◽  
Author(s):  
Santiago Hernández-Allés ◽  
Sebastián Albertí ◽  
Xavier Rubires ◽  
Susana Merino ◽  
Juan M. Tomás ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Resistant Mutant ◽  
Terminal Sequence ◽  
E Coli ◽  
Isolation Methods ◽  
Phage Resistant Mutant

FC3-11, a bacteriophage specific for the Klebsiella pneumoniae porin OmpK36, was isolated by its ability to infect Escherichia coli strains expressing the cloned OmpK36 porin. Porin OmpK36 was shown to be the receptor for phage FC3-11 by the observations that K. pneumoniae and E. coli strains that do not express OmpK36 were resistant to phage FC3-11, the purified porin inactivated the phage, and mutants selected for FC3-11 resistance had lost OmpK36. The outer membrane protein OmpK35 was isolated from a K. pneumoniae phage-resistant mutant by using porin isolation methods and was shown to contain an N-terminal sequence typical of enterobacterial porins. Bacteriophage FC3-11, alone or in combination with previously described lipopolysaccharide-specific phages, is a valuable tool to obtain OmpK36-porinless mutants.Key words: Klebsiella pneumoniae, porins, bacteriophage.

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.

scholarly journals Carbapenem Resistance in Escherichia coli Associated with Plasmid-Determined CMY-4 β-Lactamase Production and Loss of an Outer Membrane Protein

1999 ◽  
Vol 43 (5) ◽  
pp. 1206-1210 ◽  
Author(s):  
Paul D. Stapleton ◽  
Kevin P. Shannon ◽  
Gary L. French
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Carbapenem Resistance ◽  
Nucleotide Position ◽  
E Coli ◽  
Class C ◽  
The Difference ◽  
High Level

ABSTRACT Three cefoxitin-resistant Escherichia coli isolates from stool specimens of a patient with leukemia were either resistant, intermediate, or sensitive to imipenem. Conjugation experiments showed that cefoxitin resistance, but not imipenem resistance, was transferable. All isolates were shown by isoelectric focusing to produce two β-lactamases with isoelectric points of 5.4 (TEM-1, confirmed by sequencing of a PCR product) and >8.5 (consistent with a class C β-lactamase). The gene coding for the unknown β-lactamase was cloned and sequenced and revealed an enzyme which had 99.9% sequence identity with the plasmid-determined class C β-lactamase CMY-2. The cloned β-lactamase gene differed frombla CMY-2 at one nucleotide position that resulted in an amino acid change, tryptophan to arginine at position 221. We propose that this enzyme be designated CMY-4. Both the imipenem-resistant and -intermediate isolates lacked a 38-kDa outer membrane protein (OMP) that was present in the imipenem-sensitive isolate. The lack of an OMP alone did not explain the difference in carbapenem susceptibilities observed. However, measurement of β-lactamase activities (including measurements under conditions where TEM-1 β-lactamase was inhibited) indicated that the imipenem-intermediate isolate expressed six- to eightfold less β-lactamase than did the other isolates. This study illustrates that carbapenem resistance in E. coli can arise from high-level expression of plasmid-mediated class C β-lactamase combined with an OMP deficiency. Furthermore, in the presence of an OMP deficiency, the level of expression of a plasmid-mediated class C β-lactamase is an important factor in determining whether E. coliisolates are fully resistant to carbapenems.

In vitro assembly of outer membrane protein PhoE of E. coli.

1996 ◽  
pp. 71-78
Author(s):  
Carmen Jansen ◽  
Hans de Cock ◽  
Patrick Van Gelder ◽  
Jan Tommassen
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
E Coli ◽  
In Vitro Assembly

Tricarboxylate transport in a Cit+Escherichia coli: evidence for the role of an outer membrane protein

1984 ◽  
Vol 30 (7) ◽  
pp. 916-921 ◽  
Author(s):  
Juan. M. Tomás ◽  
William W. Kay
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
E Coli ◽  
Single Carbon Source ◽  
Resistant Mutants ◽  
Induction Times ◽  
Growth Induction

A strain of Escherichia coli of bovine origin able to use tricarboxylates as single carbon source is described. Tricarboxylate utilization (Cit+) and fluorocitrate sensitivity (FCs) could be transferred conjugatively to E. coli K12 and were not plasmid borne. No evidence was found for tct gene products of Salmonella typhimurium. A citrate-inducible outer membrane protein of 21–22 kilodaltons (kd) was found only in Cit+ strains. A protein (21–22 kd) protein was also found in wild-type E. coli K12 and in fluorocitrate-resistant mutants of Cit+ strains, but it was present in a cryptic form no longer inducible by citrate. Fluorocitrate-resistant mutants of Cit+ strains were still able to transport citrate by a fuorocitrate-insensitive system. High levels of the 22-kd protein correlated with reduced growth induction times on citrate and with the ability to effectively transport citrate.

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