Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.
Proteins isolated from the outer membrane of Gram-negative bacteria.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
Proteins found in any species of bacterium.
A family of voltage-gated eukaryotic porins that form aqueous channels. They play an essential role in mitochondrial CELL MEMBRANE PERMEABILITY, are often regulated by BCL-2 PROTO-ONCOGENE PROTEINS, and have been implicated in APOPTOSIS.
A rapid-growing, nonphotochromogenic species of MYCOBACTERIUM originally isolated from human smegma and found also in soil and water. (From Dorland, 28th ed)
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
A foul-smelling diamine formed by bacterial decarboxylation of lysine.
A species of gram-negative rod-shaped bacteria found ubiquitously and formerly called Comamonas acidovorans and Pseudomonas acidovorans. It is the type species of the genus DELFTIA.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
A genus of gram-negative bacteria widely distributed in fresh water as well as marine and hypersaline habitats.
A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Proteins obtained from ESCHERICHIA COLI.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A genus of gram-negative, aerobic, coccoid bacteria whose organisms are part of the normal flora of the oropharynx, nasopharynx, and genitourinary tract. Some species are primary pathogens for humans.
Gram-negative gas-producing rods found in feces of humans and other animals, sewage, soil, water, and dairy products.
A serotype of SALMONELLA ENTERICA which is the etiologic agent of TYPHOID FEVER.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Substances that reduce the growth or reproduction of BACTERIA.
A specific species of bacteria, part of the BORRELIA BURGDORFERI GROUP, whose common name is Lyme disease spirochete.
Gram-negative helical bacteria, in the genus BORRELIA, that are the etiologic agents of LYME DISEASE. The group comprises many specific species including Borrelia afzelii, Borellia garinii, and BORRELIA BURGDORFERI proper. These spirochetes are generally transmitted by several species of ixodid ticks.
An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.
Infections with bacteria of the genus BORRELIA.
Arthropods, other than insects and arachnids, which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.
Detailed account or statement or formal record of data resulting from empirical inquiry.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Family of gram-positive, facultatively anaerobic bacteria, in the order Bacillales. Genera include Gemella, Macrococcus, Salinicoccus, and STAPHYLOCOCCUS.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The technique of washing tissue specimens with a concentrated solution of a heavy metal salt and letting it dry. The specimen will be covered with a very thin layer of the metal salt, being excluded in areas where an adsorbed macromolecule is present. The macromolecules allow electrons from the beam of an electron microscope to pass much more readily than the heavy metal; thus, a reversed or negative image of the molecule is created.
The sole species of the genus Oxalobacter consisting of straight or curved gram-negative rods with rounded ends. Cells are nonmotile, nonsporing, and use oxylates as the only source of CARBON and energy, with formate and CARBON DIOXIDE as end products. They are isolated from lake sediments and from the rumen or large bowel of humans and animals. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
Bacteriocins elaborated by strains of Escherichia coli and related species. They are proteins or protein-lipopolysaccharide complexes lethal to other strains of the same species.
The etiologic agent of CHOLERA.
A family of gram-negative bacteria whose members predominate in the bacterial flora of PLANKTON; FISHES; and SEAWATER. Some members are important pathogens for humans and animals.
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.
A nonreducing disaccharide composed of GLUCOSE and FRUCTOSE linked via their anomeric carbons. It is obtained commercially from SUGARCANE, sugar beet (BETA VULGARIS), and other plants and used extensively as a food and a sweetener.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Method of making images on a sensitized surface by exposure to light or other radiant energy.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.
A species of gram-negative, aerobic bacteria primarily found in purulent venereal discharges. It is the causative agent of GONORRHEA.
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.

Safety and immunogenicity of a Pseudomonas aeruginosa hybrid outer membrane protein F-I vaccine in human volunteers. (1/1946)

A hybrid protein [Met-Ala-(His)6OprF190-342-OprI21-83] consisting of the mature outer membrane protein I (OprI) and amino acids 190 to 342 of OprF of Pseudomonas aeruginosa was expressed in Escherichia coli and purified by Ni2+ chelate-affinity chromatography. After safety and pyrogenicity evaluations in animals, four groups of eight adult human volunteers were vaccinated intramuscularly three times at 4-week intervals and revaccinated 6 months later with either 500, 100, 50, or 20 microg of OprF-OprI adsorbed onto A1(OH)3. All vaccinations were well tolerated. After the first vaccination, a significant rise of antibody titers against P. aeruginosa OprF and OprI was measured in volunteers receiving the 100- or the 500-microg dose. After the second vaccination, significant antibody titers were measured for all groups. Elevated antibody titers against OprF and OprI could still be measured 6 months after the third vaccination. The capacity of the elicited antibodies to promote complement binding and opsonization could be demonstrated by a C1q-binding assay and by the in vitro opsonophagocytic uptake of P. aeruginosa bacteria. These data support the continued development of an OprF-OprI vaccine for use in humans.  (+info)

Distinct sensitivities of OmpF and PhoE porins to charged modulators. (2/1946)

The inhibition of the anion-selective PhoE porin by ATP and of the cation-selective OmpF porin by polyamines has been previously documented. In the present study, we have extended the comparison of the inhibitor-porin pairs by investigating the effect of anions (ATP and aspartate) and positively charged polyamines (spermine and cadaverine) on both OmpF and PhoE with the patch-clamp technique, and by comparing directly the gating kinetics of the channels modulated by their respective substrates. The novel findings reported here are (1) that the activity of PhoE is completely unaffected by polyamines, and (2) that the kinetic changes induced by ATP on PhoE or polyamines on OmpF suggest different mechanisms of inhibition. ATP induces a high degree of flickering in the PhoE-mediated current and appears to behave as a blocker of ion flow during its presumed transport through PhoE. Polyamines modulate the kinetics of openings and closings of OmpF, in addition to promoting a blocker-like flickering activity. The strong correlation between sensitivity to inhibitors and ion selectivity suggests that some common molecular determinants are involved in these two properties and is in agreement with the hypothesis that polyamines bind inside the pore of cationic porins.  (+info)

Enhanced bioaccumulation of heavy metal ions by bacterial cells due to surface display of short metal binding peptides. (3/1946)

Metal binding peptides of sequences Gly-His-His-Pro-His-Gly (named HP) and Gly-Cys-Gly-Cys-Pro-Cys-Gly-Cys-Gly (named CP) were genetically engineered into LamB protein and expressed in Escherichia coli. The Cd2+-to-HP and Cd2+-to-CP stoichiometries of peptides were 1:1 and 3:1, respectively. Hybrid LamB proteins were found to be properly folded in the outer membrane of E. coli. Isolated cell envelopes of E. coli bearing newly added metal binding peptides showed an up to 1.8-fold increase in Cd2+ binding capacity. The bioaccumulation of Cd2+, Cu2+, and Zn2+ by E. coli was evaluated. Surface display of CP multiplied the ability of E. coli to bind Cd2+ from growth medium fourfold. Display of HP peptide did not contribute to an increase in the accumulation of Cu2+ and Zn2+. However, Cu2+ ceased contribution of HP for Cd2+ accumulation, probably due to the strong binding of Cu2+ to HP. Thus, considering the cooperation of cell structures with inserted peptides, the relative affinities of metal binding peptide and, for example, the cell wall to metal ion should be taken into account in the rational design of peptide sequences possessing specificity for a particular metal.  (+info)

In-vitro selection of porin-deficient mutants of two strains of Klebsiella pneumoniae with reduced susceptibilities to meropenem, but not to imipenem. (4/1946)

We have evaluated the ability of imipenem and meropenem to select, in vitro, resistant mutants of two clinical isolates of Klebsiella pneumoniae producing both SHV and TEM beta-lactamases. Only meropenem selected mutants of both isolates for which the MICs of meropenem, but not imipenem, were markedly higher than those for the parent strains; the MICs of several other beta-lactam antibiotics, including beta-lactam/beta-lactamase inhibitor combinations, for these mutants were also higher than those for the parent strains. In contrast, the MICs for the imipenem-selected mutants were the same as, or similar to, those for the parent strains. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis revealed that an outer membrane protein in both parent strains was absent in the meropenem-selected mutants, but not in the imipenem-selected mutants. This protein is likely to be a porin, the absence of which is presumably associated with impaired beta-lactam permeability and, therefore, the reduced susceptibilities to these antibiotics exhibited by the mutant strains. We believe that this is the first report of the in-vitro selection of porin-deficient mutants of K. pneumoniae following exposure to meropenem.  (+info)

Single channel analysis of recombinant major outer membrane protein porins from Chlamydia psittaci and Chlamydia pneumoniae. (5/1946)

We recently demonstrated that the major outer membrane protein of Chlamydia psittaci, the primary vaccine candidate for combating chlamydial infections, functions as a porin-like ion channel. In this study, we have cloned, expressed and functionally reconstituted recombinant major outer membrane proteins from C. psittaci and Chlamydia pneumoniae and analysed them at the single channel level. Both form porin-like ion channels that are functionally similar to those formed by native C. psittaci major outer membrane protein. Also, like the native channels, recombinant C. psittaci channels are modified by a native major outer membrane protein-specific monoclonal antibody. This is the first time that native function has been demonstrated for recombinant chlamydial major outer membrane proteins. Future bilayer reconstitution will provide a strategy for detailed structure/function studies of this new subclass of bacterial porins and the work also has important implications for successful protein refolding and the development of improved subunit vaccines.  (+info)

Site-directed mutagenesis of loop L3 of sucrose porin ScrY leads to changes in substrate selectivity. (6/1946)

The difference in substrate selectivity of the maltodextrin (LamB) and sucrose (ScrY) porins is attributed mainly to differences in loop L3, which is supposed to constrict the lumen of the pores. We show that even a single mutation (D201Y) in loop L3 leads to a narrowing of the substrate range of ScrY to that resembling LamB. In addition, we removed the putative N-terminal coiled-coil structure of ScrY and studied the effect of this deletion on sucrose transport.  (+info)

Escherichia coli outer membrane protein TolC is involved in production of the peptide antibiotic microcin J25. (7/1946)

A Tn5 insertion in tolC eliminated microcin J25 production. The mutation had little effect on the expression of the microcin structural gene and presumably acted by blocking microcin secretion. The tolC mutants carrying multiple copies of the microcin genes were less immune to the microcin. TolC is thus likely a component of a microcin export complex containing the McjD immunity protein, an ABC exporter.  (+info)

Bcl-xL prevents cell death following growth factor withdrawal by facilitating mitochondrial ATP/ADP exchange. (8/1946)

Growth factor withdrawal is associated with a metabolic arrest that can result in apoptosis. Cell death is preceded by loss of outer mitochondrial membrane integrity and cytochrome c release. These mitochondrial events appear to follow a relative increase in mitochondrial membrane potential. This change in membrane potential results from the failure of the adenine nucleotide translocator (ANT)/voltage-dependent anion channel (VDAC) complex to maintain ATP/ADP exchange. Bcl-xL expression allows growth factor-deprived cells to maintain sufficient mitochondrial ATP/ADP exchange to sustain coupled respiration. These data demonstrate that mitochondrial adenylate transport is under active regulation. Efficient exchange of ADP for ATP is promoted by Bcl-xL expression permitting oxidative phosphorylation to be regulated by cellular ATP/ADP levels and allowing mitochondria to adapt to changes in metabolic demand.  (+info)

The neisserial porins are the major protein components of the outer membrane of the pathogenic Neisseria (N. meningitidis and N. gonorrhoeae). They have been shown to be able to enhance the immune response to poorly immunogenic substances (e.g., polysaccharides, peptides, glycolipids, etc.). To explore the basis of their potent adjuvant activity, the effect of the neisserial porins on T-B cell interactions and T cell costimulation was examined. Neisserial porins increased the surface expression of the costimulatory ligand B7-2 (CD86) but did not affect the expression of B7-1 (CD80). In addition, incubation with the neisserial porins increased the T lymphocyte costimulatory ability of B lymphocytes, which was inhibited by anti-B7-2 but not anti-B7-1 monoclonal antibodies. Upregulation of B7-2 on the surface of B lymphocytes may be the mechanism behind the immunopotentiating activity of neisserial porins. ...
TY - JOUR. T1 - Lipopolysaccharide-free Escherichia coli OmpF and Pseudomonas aeruginosa protein P porins are functionally active in lipid bilayer membranes. AU - Parr, T. R.. AU - Poole, K.. AU - Crockford, G. W.K.. AU - Hancock, R. E.W.. PY - 1986/1/1. Y1 - 1986/1/1. UR - http://www.scopus.com/inward/record.url?scp=0022466549&partnerID=8YFLogxK. U2 - 10.1128/jb.165.2.523-526.1986. DO - 10.1128/jb.165.2.523-526.1986. M3 - Article. C2 - 3003028. AN - SCOPUS:0022466549. VL - 165. SP - 523. EP - 526. JO - Journal of bacteriology. JF - Journal of bacteriology. SN - 0021-9193. IS - 2. ER - ...
The membrane assembly of outer membrane proteins is more complex than that of transmembrane helical proteins owing to the intervention of many charged and polar residues in the membrane. Accordingly, the predictive accuracy of transmembrane beta strands is considerably lower than that of transmembrane alpha helices. In this paper we develop a set of conformational parameters for membrane spanning beta strands. We formulate an algorithm to predict the transmembrane beta strands in the family of bacterial porins based on the conformational parameters and surrounding hydrophobicities of amino acid residues. A Fortran program has been developed which takes the amino acid sequence as the input file and gives the predicted transmembrane beta strand as output. The present method predicts at an accuracy level of 82% for all the bacterial porins considered.
The Tar chemoreceptor of Escherichia coli is a membrane-bound sensory protein that facilitates bacterial chemotaxis in response to aspartate. The EnvZ molecule has a membrane topology similar to Tar and is a putative osmosensor that is required for osmoregulation of the genes for the major outer membrane porin proteins, OmpF and OmpC. The cytoplasmic signaling domain of Tar was replaced with the carboxyl portion of EnvZ, and the resulting chimeric receptor activated transcription of the ompC gene in response to aspartate. The activation of ompC by the chimeric receptor was absolutely dependent on OmpR, a transcriptional activator for ompF and ompC. ...
Structural relatedness of enteric bacterial porins assessed with monoclonal antibodies to Salmonella typhimurium OmpD and OmpC.: The immunochemistry and structu
Outer membrane porin D is a protein family containing bacterial outer membrane porins which are involved in transport of cationic amino acids, peptides, antibiotics and other compounds. It was also described as having some serine protease activity. However many of these proteins are not peptidases and are classified as non-peptidase homologues as they either have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for the catalytic activity of peptidases in the S43 family. Yoshihara E, Yoneyama H, Ono T, Nakae T (June 1998). Identification of the catalytic triad of the protein D2 protease in Pseudomonas aeruginosa. Biochem. Biophys. Res. Commun. 247 (1): 142-5. doi:10.1006/bbrc.1998.8745. PMID 9636669. This article incorporates text from the public domain Pfam and InterPro ...
The proper functioning of proteins requires their correct localization to predetermined cellular locations. In the gram-negative bacterium Escherichia coliK-12, a special class of proteins known as porins (24) must be properly targeted and assembled in the outer membrane to form channels that facilitate the diffusion of hydrophilic solutes. The atomic structure showed that porins primarily consist of antiparallel β strands that are arranged in a pseudocyclic β-barrel structure, which encloses a water-filled channel (6, 29). On the periplasmic side, β strands are adjoined by short turns, whereas long loops provide connections on the medium-exposed side. Although the majority of loops are surface exposed, one or more loops fold inward thus restricting the channel. Surface-exposed loops are often utilized by bacteriophages as their receptors (35, 36, 37).. Outer membrane proteins (OMPs) are synthesized in the cytoplasm as precursors with an amino-terminal signal sequence that assists in exiting ...
Gram-negative bacteria are protected against external attack by an outer membrane. However, general diffusion porins located in this membrane allow the entry, by simple diffusion, of small molecules and, among them, antibiotics (beta-lactams and fluoroquinolones). Strains of bacteria resistant to beta-lactams have shown either a low porin density in the outer membrane, or some mutations at the level of porins affecting their internal size. Understand how antibiotics diffuse through these porins can help researcher to develop new antibiotics with an improved penetration especially when resistance becomes a serious problem for infectious disease. Recent experimental investigations pointed out how the diffusion of antibiotics through a porin is a molecular-based process: during diffusion the antibiotics interact strongly with the amino acids of the porin. Changing either the charge or the hydrophobicity of antibiotics the interaction strenght with the porin changes as well. Using a recent algorithm ...
A strain of Escherichia coli, selected on the basis of its resistance to colicin N, reveals distinct structural and functional alterations in unspecific OmpF porin. A single mutation [Gly-119--,Asp (G119D)] was identified in the internal loop L3 that contributes critically to the formation of the construction inside the lumen of the pore. X-ray structure analysis to a resolution of 3.0 A reveals a locally altered peptide backbone, with the side chain of residue Asp-119 protruding into the channel, causing the area of the constriction (7 x 11 A in the wild type) to be subdivided into two intercommunicating subcompartments of 3-4 A in diameter. The functional consequences of this structural modification consist of a reduction of the channel conductance by about one-third, of altered ion selectivity and voltage gating, and of a decrease of permeation rates of various sugars by factors of 2-12. The structural modification of the mutant protein affects neither the beta-barrel structure nor those ...
Recombinant P.IB (porB) protein (Tagged) is an Escherichia coli Full length protein 20 to 331 aa range, | 90% purity and validated in SDS-PAGE.
Sucrose-specific porin, molecular model. Porins are proteins that span cell membranes and act as a channel through which specific molecules can diffuse. - Stock Image F009/5873
The Escherichia coli porin OmpG, which acts as an efficient unspecific channel for mono-, di- and trisaccharides, has been purified and crystallized in two dimensions. Projection maps of two different crystal forms of OmpG at 6 A resolution show that the protein has a beta-barrel structure character …
1GFM: Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis.
The Mla pathway is hypothesized to be an ATP binding cassette transport system in Escherichia coli that maintains outer membrane asymmetry. Outer membrane proteins C (OmpC) and F (OmpF) have been shown to interact with MlaA, a key lipoprotein in the Mla pathway. ...
figure taken from the reference below). Murein means peptidoglycan cell wall and the cytoplasm denotes the inside of the cell. In this scenario, the double-membraned proto-bacteria (which has spend the last half-a-billion years or so evolving a well adjusted double membrane system) suddenly looses the outer membrane. A very simple genetic change would lead to a massively overgrown cell wall, which would rip the outer membrane away. The cell looses all its outer membrane porins, and signal systems, but in return gains a highly protective cell wall, which potentially allows it to survive in different niches. How these aspects are lost genetically is another matter, and the paper rather hand-waves away by saying that unused genes tend to get lost eventually. Which is true in bacteria, they have such a small genome they dont want it getting filled up with unnecessary genes, but I have a feeling genes tend to leave something behind. Even so, the question of where the now-unnecessary genes go is ...
1GFN: Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis.
1.B.68 The Putative Beta Barrel Porin-5 (BBP5) Superfamily. The BBP5 family consists of proteins homologous to the E. coli YfaZ protein. These proteins are predicted to be transmembrane beta barrel porins by the BOMP program, and they show significant sequence similarity to members of the large superfamily of porins. As of 8/2013, no member seems to have been functionally characterized. ...
Maltoporin allows permeation of long maltodextrin chains. It tightly binds the amphiphilic sugar, offering both hydrophobic interactions with a helical lane of aromatic residues and H bonds with ionic side chains. The minimum-energy path of maltohexaose translocation is obtained by the conjugate pea …
Phylogenetic analysis was utilized to investigate biological relationships (tissue tropism, disease presentation, and epidemiologic success), as evidenced by coevolution, among human strains ofChlamydia trachomatis. Nucleotide sequences ofomp1, the gene encoding the major outer membrane protein (MOMP) of C. trachomatis, were determined for 40 strains representing 11 serovars. These data were combined with availableomp1 sequences from GenBank for an analysis encompassing a total of 69 strains representing 17 serovars infecting humans. Phylogenetic analysis of the nucleotide and inferred amino acid sequences showed no evolutionary relationships among serovars that corresponded to biological or pathological phenotypes (tissue tropism, disease presentation, and epidemiologic success). In addition, no specific residues that may have evolved to play a role in determining biologically relevant characteristics of chlamydia, such as tissue specificity, disease presentation, and epidemiologic success, ...
A vaccine against C. trachomatis infection has proven difficult to develop. Early vaccine studies showed that whole inactivated bacterial cells administered intramuscularly were partially protective in human and primate trials. Primate vaccine trials and human experimental infection studies suggested that C. trachomatis immunity was in part strain specific, and the identification of MOMP as the strain-specific antigen of C. trachomatis quickly focused vaccine efforts on this protein. In general, use of MOMP or peptide epitopes derived from it as a vaccine has engendered variable or no protective immunity in a variety of animal model systems. The best results were observed when MOMP was used as a structurally intact molecule, suggesting that conformationally intact antigenic sites on the molecule are important for protective immunity.. We previously reported that MOMP DNA administered parenterally was also partially effective in inducing protective immunity against lung infection with MoPn. The ...
This entry represents both eukaryotic mitochondrial porins and Tom40 proteins.. Eukaryotic mitochondrial porins are voltage-dependent anion-selective channels (VDAC) that behave as general diffusion pores for small hydrophilic molecules [ (PUBMED:8031826) (PUBMED:1384178) (PUBMED:1689252) (PUBMED:2442148) ]. The channels adopt an open conformation at low or zero membrane potential and a closed conformation at potentials above 30-40 mV. The eukaryotic mitochondrial porins are beta-barrel proteins, composed of between 12 to 16 beta-strands that span the mitochondrial outer membrane. Yeast contains two members of this family (genes POR1 and POR2); vertebrates have at least three members (genes VDAC1, VDAC2 and VDAC3) [ (PUBMED:8812436) ]. They are related to the mitochondrial import receptor subunit Tom40 proteins, sharing a common evolutionary origin and structure [ (PUBMED:22178864) ]. Tom40 is a mitochondrion outer membrane protein and a component of the TOM (translocator of the outer ...
TY - JOUR. T1 - The role of mitochondrial porins and the permeability transition pore in learning and synaptic plasticity. AU - Weeber, Edwin J.. AU - Levy, Michael. AU - Sampson, Margaret J.. AU - Anflous, Keltoum. AU - Armstrong, Dawna L.. AU - Brown, Sarah E.. AU - David Sweatt, J.. AU - Craigen, William J.. PY - 2002/5/24. Y1 - 2002/5/24. N2 - Mitochondrial outer membrane permeability is conferred by a family of porin proteins. Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals. Because mitochondrial porins have significant roles in diverse cellular processes including regulation of mitochondrial ATP and calcium flux, we sought to determine their importance in learning and synaptic plasticity in mice. We show that fear conditioning and spatial learning are disrupted in porin-deficient mice. Electrophysiological recordings of porin-deficient hippocampal slices reveal deficits in long and ...
In the current study, the construction of a toxR+ V. cholerae strain that expresses the ToxR-repressed porin OmpT in place of the ToxR-activated porin OmpU has allowed us to dissect the role these porins play in V. cholerae pathogenesis. Amazingly, merely substituting one outer membrane porin for another resulted in a number of attenuated pathogenic properties, including bile resistance, virulence factor expression, and intestinal colonization. ToxR-dependent regulation of outer membrane porins appears to have preceded the evolution of V. cholerae, because ToxR performs similar functions in other members of the Vibrionaceae (14, 17). However, these other bacteria do not have the additional regulatory factors TcpP and ToxT whose genes are located on the V. cholerae-specific pathogenicity island VPI (30). The recruitment of the ancestral ToxR protein into the virulence regulatory cascade involving recently acquired elements ties porin regulation to pathogenesis. We suggest that the contribution of ...
1.B.8 The Mitochondrial and Plastid Porin (MPP) Family Porins of the MPP family are found in eukaryotic organelles. The organelles include mitochondria of many eukaryotes as well as chloroplasts and plastids of plants. The best characterized members of the MPP family are the voltage-dependent anion-selective channel (VDAC) porins in the mitochondrial outer membrane. These porins have an estimated channel diameter of 2.5-3 nm. Topological models have been proposed in which VDAC consists of an N-terminal, globular α-helix and (1) 12 or 13 β-strands, (2) 16 β-strands or (3) 19 β-strands (now favored; see below) (Casadio et al., 2002). VDAC also appears to be present in plasma membranes (De Pinto et al., 2010). Prostacyclin receptor-mediated ATP release from ethrocytes requires VDAC (Sridharan et al., 2011). Phylogenetic analyses of eukaryotic VDAC proteins from diverse organisms have been reported (Wojtkowska et al. 2012). Over-oxidation of cysteines and succinylation of cysteines in VDACs has ...
Ertapenem is a potent carbapenem antibiotic for most clinical isolates of Klebsiella pneumoniae, with a typical MIC at which 90% of the isolates tested are inhibited of 0.03 to 0.06 μg/ml (6, 9), but occasional strains for which the MICs are ≥16 μg/ml have been detected (6, 7). In one such strain resistance was dependent on the presence of the plasmid-mediated extended-spectrum β-lactamase (ESBL) SHV-2 and additional host events presumably affecting ertapenem permeativity (7). Further studies were undertaken to elucidate the contribution of β-lactamase and host mutation to such exceptional resistance.. The K. pneumoniae strain for which the ertapenem MIC was 16 μg/ml was treated with ethidium bromide to cure the resident plasmid. The ertapenem MIC for the resulting strain, C2, was still elevated at l μg/ml, and the strain was found to be defective in expression of outer membrane porins OmpK35 and OmpK36 (10). To evaluate the influence of different β-lactamases on the ertapenem ...
Our results provide some important confirmation of theories regarding OprF structure and function. We have demonstrated that residues in the C-terminal domain of OprF are required for strong peptidoglycan association, as previously proposed (9). Expression of our truncated OprF mutants in E. coli orP. aeruginosa suggests that the first 154 to 163 aa of OprF are needed to produce a stable protein. This possibility is in strong agreement with the proposal that the first 160 aa of OprF form a β-barrel structure and suggests that residues critical to proper conformation of this domain are present between aa 154 and 163. The residues between aa 150 and 160 conform to the consensus sequence of the 16th C-terminal β strand of the porin superfamily (21, 22). Studies of other porins, such as E. coli PhoE, suggest that a phenylalanine residue in this terminal strand (equivalent to OprF residue 160) is critical for protein stability and proper folding (8). Our results may thus reflect deletion of such a ...
Shop Major outer membrane protein ELISA Kit, Recombinant Protein and Major outer membrane protein Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
Connexins (Cxs) and pannexins (Panxs) are highly regulated large-pore channel-forming proteins that participate in cellular communication via small molecular exchange with the extracellular microenvironment, or in the case of connexins, directly between cells. in Cx40?/? mice was further exaggerated in double knockout mice. Thus, while gestation and gross development were conserved in Cx40?/?Panx1?/? mice, they exhibit cardiac hypertrophy, hypertension, and impaired endothelial-mediated vasodilation that phenocopies Cx40?/? mice. Nevertheless, the augmented renin homeostasis observed in the double knockout mice suggests that both Cx40 and Panx1 may play an integrative role. [3C5]. Conversely, the most well-understood pannexin, pannexin1 (Panx1), has been demonstrated to form large-pore membrane channels, which facilitate autocrine/paracrine-mediated signaling via the release of purine nucleotides, most notably ATP [6]. Within the mammalian cardiovascular system (cardiac tissue and peripheral ...
As we compare the condition of the world to-day with its condition at any former period, we find a marked differ- ence in the sentiments of the masses. The spirit of inde- pendence is now abroad, and men are not so easily blind- folded, deceived and led by rulers and politicians, and therefore they will not submit to the yokes of former days. This change of public sentiment has not been a gradual one from the very beginning of mans effort to govern L t pi- self, but clearly marked only as far back as the sixteenth century ; and its progress has been most rapid within the last fifty years. This change, therefore, is not the result of the experience of past ages, but is the natural result of the recent increase and general diffusion of knowledge among the masses of mankind. The preparation for this general diffusion of knowledge began with the invention of printing, about 1440 A. D., and the consequent multiplica- tion of books and news periodicals. The influence of this invention in the general ...
2017. Trebosc, V. et al. Reversion of Antibiotic Resistance in Mycobacterium tubercolosis by spiroisoxazoline SMARt-420″. Science 2017. Mar 2017 Vol. 355, Issue 6330, pp. 1206-1211 doi: 10.1126/science.aag1006. A. Gilardi, S.P. Bhamidimarri, M. Broenstrup, U. Bilitewski, R.K.R. Marreddy, K.M. Pos, L. Benier, P. Gribbon, M. Winterhalter, B. Windshuegel. Biophysical characterization of E. coli TolC interaction with the known blocker hexaamminecobalt.Biochim Biophys Acta. 2017 Nov;1861(11 Pt A):2702-2709. Epub 2017 Jul 23. doi: 10.1016/j.bbagen.2017.07.014. Ramaswamy, V. K., Vargiu, A.V., Malloci, G., Dreier, J. G., & Ruggerone, P. Molecular rationale behind the differential substrate specificity of bacterial RND multi-drug transporters. Scientific Reports 7, Article number: 8075(2017) doi:10.1038/s41598-017-08747-8. Harsha Bajaj, Silvia Acosta-Gutiérrez, Igor Bodrenko, Giuliano Malloci, Mariano Andrea Scorciapino, Mathias Winterhalter and Matteo Ceccarelli. Bacterial Outer Membrane Porins ...
Molecular dynamics simulations by Department of Biochemistrys Dr Phillip Stansfeld, in the lab of Professor Mark Sansom, have helped to reveal how bacteria construct a barrier against antibiotics and the bodys immune system.
The asymmetric outer membrane of Gram-negative bacteria is formed of the inner leaflet with phospholipids and the outer leaflet with lipopolysaccharides (LPS). Outer membrane protein F (OmpF) is a trimeric porin responsible for the passive transport of small molecules across the outer membrane of Escherichia coli. Here, we report the impact of different levels of heterogeneity in LPS environments on the structure and dynamics of OmpF using all-atom molecular dynamics simulations. The simulations provide insight into the flexibility and dynamics of LPS components that are highly dependent on local environments, with lipid A being the most rigid and O-antigen being the most flexible. Increased flexibility of O-antigen polysaccharides is observed in heterogeneous LPS systems, where the adjacent O-antigen repeating units are weakly interacting and thus more dynamic, compared to homogeneous LPS systems in which LPS interacts strongly with each other with limited overall flexibility due to dense ...
Pseudomonas aeruginosa is an important opportunistic pathogen that can cause chronic and often life-threatening infections of the respiratory tract, particularly in individuals with cystic fibrosis (CF). Because infections with P. aeruginosa remain the major cause of the high morbidity and mortality of CF, a vaccine against P. aeruginosa would be very useful for preventing this disorder. The outer membrane protein F (OprF) of P. aeruginosa is a promising vaccine candidate and various B cell epitopes within OprF have been identified. Given that adenovirus (Ad) vectors have strong immunogenic potential and can function as adjuvants for genetic vaccines, the present study evaluates the immunogenic and protective properties of a novel replication-deficient Ad vector in which the Ad hexon protein was modified to include a 14-amino acid epitope of P. aeruginosa OprF (Epi8) in loop 1 of the hypervariable region 5 of the hexon (AdZ.Epi8). Immunization of C57BL/6 mice with AdZ.Epi8 resulted in detectable ...
Dispensable loops shield the functionally-important extracellular loops of the essential Gram-negative bacterial outer membrane protein LptD from antibody interference.
Anand A, LeDoyt M, Karanian C, Luthra A, Koszelak-Rosenblum M, Malkowski MG, Puthenveetil R, Vinogradova O, Radolf JD. Bipartite Topology of Treponema pallidum Repeat Proteins C/D and I: OUTER MEMBRANE INSERTION, TRIMERIZATION, AND PORIN FUNCTION REQUIRE A C-TERMINAL ß-BARREL DOMAIN. J Biol Chem. 2015 May 08; 290(19):12313-31 ...
In biochemistry, a protein trimer is a macromolecular complex formed by three, usually non-covalently bound, macromolecules like proteins or nucleic acids. A homo-trimer would be formed by three identical molecules. A hetero-trimer would be formed by three different macromolecules. Type II Collagen is an example of homo-trimeric protein. Porins usually arrange themselves in membranes as trimers. ...
Shop Oligogalacturonate-specific porin ELISA Kit, Recombinant Protein and Oligogalacturonate-specific porin Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
A - Tilt: 3° - Segments: 1( 6- 16), 2( 31- 39), 3( 43- 50), 4( 68- 78), 5( 85- 92), 6( 111- 120), 7( 128- 136), 8( 151- 160), 9( 167- 174), 10( 192- 201), 11( 204- 214), 12( 223- 230), 13( 237- 244), 14( 259- 268 ...
A - Tilt: 5° - Segments: 1( 6- 16), 2( 31- 41), 3( 42- 50), 4( 68- 78), 5( 84- 92), 6( 111- 122), 7( 127- 135), 8( 151- 161), 9( 166- 173), 10( 192- 200), 11( 204- 212), 12( 234- 244), 13( 247- 256), 14( 271- 279 ...
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Phlogenzym je obvykle dobre znášaný, ani pri dlhodobom užívaní vysokých dávok neboli pozorované nežiaduce účinky. Pôsobením enzýmov môžu nastať neškodné zmeny farby, pachu a konzistencie stolice. Počas užívania vyšších jednorázových dávok sa môžu objaviť pocity plnosti, nafukovania a výnimočne pocit nevoľnosti. Tomu sa dá zabrániť rozdelením dávky na viacero dávok v priebehu dňa. Ak tieto príznaky aj po znížení dávky pretrvávajú, poraďte sa s lekárom. Zriedka pozorované alergické reakcie (kožná vyrážka) odoznejú po vysadení lieku. Pri ich prípadnom výskyte prerušte užívanie Phlogenzymu a poraďte sa s lekárom. Zriedkavými nežiaducimi účinkami sú: bolesť hlavy, pocit hladu a zvýšená potivosť. S lekárom sa o ďalšom užívaní Phlogenzymu poraďte aj v prípade výskytu akýchkoľvek neobvyklých reakcií ...
The Dashs sock-like bootie design, which keeps out debris, is combined with arch-lasted construction for a supportive fit. Lacing is asymmetrical with offset eyelets that help to reinforce the support.
Forms a channel through the cell membrane that allows diffusion of small hydrophilic molecules (By similarity). Plays a role in maintaining mitochondrial morphology (PubMed:25190516).
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class=publication>Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href=http://www.nrbook.com/b/bookcpdf.php>Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
OprF is a major outer membrane protein from Pseudomonas aeruginosa, a homolog of OmpA from Escherichia coli. The N-terminal domains of both proteins have been demonstrated to form low conductance channels in lipid bilayers. Homology models, consisting of an eight-stranded beta-barrel, of the N-terminal domain OprF have been constructed based on the crystal structure of the corresponding domain from E. coli OmpA. OprF homology models have been evaluated via a set (6 x 10 ns) of simulations of the beta-barrel embedded within a solvated dimyristoyl-phosphatidylcholine (DMPC) bilayer. The conformational stability of the models is similar to that of the crystal structure of OmpA in comparable simulations. There is a degree of water penetration into the pore-like center of the OprF barrel. The presence of an acidic/basic (E8/K121) side-chain interaction within the OprF barrel may form a gate able to close/open a central pore. Lipid-protein interactions within the simulations were analyzed and revealed that
The protein encoded by this gene belongs to the BCL2 protein family. BCL2 family members form hetero- or homodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein forms a heterodimer with BCL2, and functions as an apoptotic activator. This protein is reported to interact with, and increase the opening of, the mitochondrial voltage-dependent anion channel (VDAC), which leads to the loss in membrane potential and the release of cytochrome c. The expression of this gene is regulated by the tumor suppressor P53 and has been shown to be involved in P53-mediated apoptosis. Multiple alternatively spliced transcript variants, which encode different isoforms, have been reported for this gene. Product Name ...
The protein encoded by this gene belongs to the BCL2 protein family. BCL2 family members form hetero- or homodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein forms a heterodimer with BCL2, and functions as an apoptotic activator. This protein is reported to interact with, and increase the opening of, the mitochondrial voltage-dependent anion channel (VDAC), which leads to the loss in membrane potential and the release of cytochrome c. The expression of this gene is regulated by the tumor suppressor P53 and has been shown to be involved in P53-mediated apoptosis. Multiple alternatively spliced transcript variants, which encode different isoforms, have been reported for this gene. Product Name ...
The protein encoded by this gene belongs to the BCL2 protein family. BCL2 family members form oligomers or heterodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein localizes to mitochondria, and functions to induce apoptosis. It interacts with and accelerates the opening of the mitochondrial voltage-dependent anion channel, which leads to a loss in membrane potential and the release of cytochrome c. This protein also interacts with the tumor suppressor P53 after exposure to cell stress. [provided by RefSeq, Jul 2008] ...
Sugar permeation through maltoporin of Escherichia coli, a trimer protein that facilitates maltodextrin translocation across outer bacterial membranes, was investigated at the single channel level. For large sugars, such as maltohexaose, elementary e
Khandelwal and colleagues succeeded in identifying the insecticidal factor. The active component was found in a large complex normally associated with the bacterial outer membrane, and was also present in or on outer membrane vesicles (OMVs) released from the bacterial surface, says Khandelwal. They then searched through OMV components and identified a small (17 kDa) toxic protein. When purified, this protein was toxic to cultured larval cells and directly killed H. armigera larvae. Gene cloning and sequencing showed this protein is related to a class of bacterial outer membrane proteins that form protrusions, called pili or fimbriae, which often help bacteria attach to host cells during infection. Similar to pili proteins, the purified 17 kDa protein self-associated to form oligomers, each of which was connected to the next by a strand. Most importantly, the recombinant 17 kDa protein killed H. armigera larvae, demonstrating its potential as a biological control agent in a world desperately in ...
An axial flow staged zone oligomerization reaction process includes the steps of passing a hydrocarbon feedstock into the lower portion of the axial flow staged zone reactor which includes axial circulation of the hydrocarbon reaction fluid serially in each of the reaction zones, passing catalyst through a constriction zone located between successive upper and lower catalytic reaction zones which includes heat exchanging of the fluids being the constriction zone within the reactor and further includes withdrawing the oligomerized product from the top of the reactor.
Introduction. The marA, soxS, ramA, acrB and ompF genes have been studied in order to characterize mechanisms of AcrAB-TolC active efflux pumps and membrane permeability alterations that reduce fluoroquinolones susceptibility in Salmonella spp. Methods. Mutations in marA, soxS, ramA, acrB and ompF genes were detected, as well as their expression levels in presence and absence of ciprofloxacin, calculating the level of change between them by qPCR. Data were analysed by using SPSS 19.0. Results. No mutations in these genes were found, but both AcrAB-TolC regulatory genes and structural acrB gene expression were affected by ciprofloxacin in both mutant strains and wild type bacterial strains (WT ...
Using mathematical models that combine population genetic and epidemiological processes, we resolve the paradox that many important pathogens appear to persist as discrete strains despite the constant exchange of genetic material. We show that dominant polymorphic determinants (that is, those that elicit the most effective immune responses) will be organized into nonoverlapping combinations as a result of selection by the host immune system, thereby defining a set of discrete independently transmitted strains. By analysing 222 isolates of Neisseria meningitidis, we show that two highly polymorphic epitopes of the outer membrane protein PorA exist in nonoverlapping combinations as predicted by this general framework. The model indicates that dominant polymorphic determinants will be in linkage disequilibrium, despite frequent genetic exchange, even though they may be encoded by several unlinked genes. This suggests that the detection of nonrandom associations between epitope regions can be employed as a
TY - JOUR. T1 - The effect of altered porin expression in Escherichia coli upon susceptibility to 4-quinolones. AU - Piddock, L J. AU - Wise, R. PY - 1986/10. Y1 - 1986/10. KW - Bacterial Proteins. KW - Escherichia coli. KW - Gene Expression Regulation. KW - Microbial Sensitivity Tests. KW - Quinolines. M3 - Article. C2 - 3533892. VL - 18. SP - 547. EP - 549. JO - Journal of Antimicrobial Chemotherapy. JF - Journal of Antimicrobial Chemotherapy. SN - 0305-7453. IS - 4. ER - ...
Simple and facilitated diffusion: Diffusion of molecules or ions through a membrane is of two types - simple and facilitated. The simple diffusion refers to the type of transfer in which the diffusing molecules or ions do not combine with the constituents of the membrane. For example, gases like oxygen, carbon dioxide etc., and water molecules diffuse readily through gas created by the random movement of fatty acyl chain of lipids. The facilitated diffusion is the movement through the membrane with the help of certain transport proteins. Membranes have several such proteins which facilitate the diffusion of solutes (Cl-, HCO3- etc.) Plasma membranes of some organisms have protein pores called, porins which are water-filled transmembrane channels.. ...
Import of porin is inhibited into tom40 mutant mitochondria. (A) Radiolabeled porin precursor (10 μl reticulocyte lysate per lane) was incubated with isolated
The expression of the clpP gene, and probably the expression of the complete clpPX operon that codes for a protease, is affected by antibiotic pressure. As the antibiotic (tetracycline) concentration increases, the gene expression also increases. The role of the induced protease could be the degradation of porins to protect the cell against the antibiotic ,CITS: [17426813],. ...
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Dobrnęliśmy do końca tej opowieści. Czy jest więc to pora na zawieszenie plakatu Fot. plakat Fot. Odczytanie wiersza Fot. A na... ...
October 1994). "Porins from plants. Molecular cloning and functional characterization of two new members of the porin family". ... Transport proteins called porins are found in the outer membranes of mitochondria and chloroplasts and are also found in ... Zeth K, Thein M (October 2010). "Porins in prokaryotes and eukaryotes: common themes and variations". The Biochemical Journal. ... that the transport proteins called porins are found in the outer membranes of mitochondria, chloroplasts and bacterial cell ...
The size and number of porins are different in different bacteria. As a result of the two factors-size of penicillin and porin- ... there are modified porins such as non-specific porins (such as OmpC and OmpF groups) that cannot transport penicillin. ... Porins are large enough to allow diffusion of most penicillins, but the rate of diffusion through them is determined by the ... Resistance in Gram-negative bacteria is due to mutational variations in the structure and number of porins. In bacteria like ...
Identification of human porins. II. Characterization and primary structure of a 31-lDa porin from human B lymphocytes (Porin ... The primary structures of "Porin 31HM" purified from human skeletal muscle membranes and of "Porin 31HL" derived from human B ... Jürgens L, Ilsemann P, Kratzin HD, Hesse D, Eckart K, Thinnes FP, Hilschmann N (July 1991). "Studies on human porin. IV. ... VDAC1 belongs to the mitochondrial porin family and is expected to share similar biological functions to the other VDAC ...
Bacterial and Eukaryotic Porins. Structure, Function, Mechanism, Wiley-VCH, ISBN 3-527-30775-3 "Swedish honors for Jacobs ...
"Dobitnici nagrade Porin 2012. , Porin". www.porin.org. Retrieved 12 November 2020. "2012 Swiss Music Awards Winners". schweizer ...
"Institut Hrvatske Glazbene Industrije - Dobitnici Porin 1999" (in Croatian). Porin. Retrieved December 17, 2010. " ... two Porin awards for Best International Album and Best International Video ("Frozen") in Croatia, and two Rockbjörnen awards ...
Porin" (in Croatian). Porin. Retrieved 19 February 2014. "The Q Awards". Everyhit.com. Retrieved 24 September 2008. "Q Awards ...
"Dobitnici po godinama - 1999". Porin. Retrieved 24 July 2018. "Dobitnici po godinama - 2000". Porin. Retrieved 24 July 2018. ... and in 1999 he was awarded the Porin award for the same composition, which was followed by another Porin award in 2000 for his ...
"Porin • 1996 - O Porinu". arhiva.porin.info. Retrieved 2018-01-14. Official website (in Croatian) [2] (biography) v t e. ... Praised for the lyrics and guitar work, the album received the Porin for the best alternative rock album of 1996. Songs like " ...
The Porin Award is a Croatian music award founded by the Croatian Phonographic Association, Croatian Musicians Union, Croatian ... "Dobitnici Po Godinama". Porin. Archived from the original on June 9, 2011. Retrieved October 5, 2016. "POP AWARDS - Annual ... ". "Porin • 2004 - O Porinu". September 4, 2011. Archived from the original on September 4, 2011. " ...
"Porin • 2009 - O Porinu". arhiva.porin.info. Retrieved 12 November 2020. "Dobitnici nagrade Porin 2012. , Porin". www.porin.org ... "Porin • Nominacije 2009 - O Porinu". arhiva.porin.info. Retrieved 12 November 2020. " ...
Porin" (in Croatian). Porin. Retrieved 19 February 2014. CS1 maint: discouraged parameter (link) "Année 2008" (in French). Les ...
"Porin • Novosti, najave, događanja". Porin.info. Retrieved 2013-05-23. CS1 maint: discouraged parameter (link) "Porin • Novosti ... In 2011, KinoKlub received a Porin, the prestigious Croatian music award, in the category 'Best New Artist'. They were also ... najave, događanja". Porin.info. Retrieved 2013-05-23. CS1 maint: discouraged parameter (link) [1] Archived November 12, 2010, ...
Porin" (in Croatian). Porin. Archived from the original on 30 January 2014. Retrieved 19 February 2014. "The Japan Gold Disc ...
"Porin • Nominacije 2009 - O Porinu". arhiva.porin.info. Retrieved 12 November 2020. "Double Q Award win for Coldplay". BBC. 6 ...
It also won Best Foreign Song at the 2010 Croatian Porin Awards. The live version of "Halo", featured on I Am... Yours: An ... "Porin • 2010" (in Croatian). Croatian Phonographic Association. Archived from the original on June 9, 2011. Retrieved May 30, ...
"Institut Hrvatske Glazbene Industrije - Dobitnici Porin 1999" (in Croatian). Porin. Retrieved December 17, 2010. "El Príncipe ...
"O Porinu Porin 1996 - Najbolji Inozemni Video Broj" [About 1996 Porin - Best Foreign Video] (in Croatian). Porin. Archived from ...
Porin 2004. HENAFF Eugène, Bourse du Travail de Paris. Lallier & Logak 2015. Marshall 2001, p. 40. Marcot 1996, p. 372. Marcot ... Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France. AERI. Retrieved 2015-05-21. Zuccotti, Susan (1999). The ...
Porin" [27th Porin Monimations] (in Croatian). porin.org. Archived from the original on 21 February 2020. Retrieved 21 February ...
Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France. AERI. Retrieved 2015-05-21. Zuccotti, Susan (1999). The ... Porin 2004. Lallier & Logak 2015. Zuccotti 1999, p. 268. Pigenet 2014. Calvès 1996. Nivet 1994, p. 90. Liaigre 2006, p. 198. ...
Porin 2004. Moorehead 2011, p. 75. Moorehead 2011, p. 75-76. Hansen 2014, p. 31. "Ce jeudi 21 août 1941, 8 heures". L'Humanité ... Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France. AERI. Retrieved 2015-05-21.. ...
Porin" [27th Porin Monimations] (in Croatian). porin.org. Archived from the original on 21 February 2020. Retrieved 21 February ...
Museohinaaja Santtu[permanent dead link]. Porin Kaupunki. Retrieved 2013-05-11. s/s REPOLA 5, 1896. Laiva.fi. Retrieved 2016-08 ...
Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France (in French). AERI. Retrieved 2015-05-21. Parmelin, ... Porin 2004. Ce jeudi 21 août 1941 ... L'Humanité. Moorehead 2011, p. 79. Moorehead 2011, p. 120. Moorehead 2011, p. 139. Besse ...
In 2004, D'Knock won the Porin music award as a master producer for the album "Ljubav" by Nina Badrić, which won 5 Porin awards ... "Porin osjetio Nininu ljubav". www.vecernji.hr. "Porin 2000. - Nominirani i nagrađeni za 2000. godinu". Archived from the ... He also produced the album "Divas" for the music group Divas that was nominated for Porin awards in 5 categories in 2000. As a ... In 2004, he won the Porin award for the producer of the year and for the best album. His Croatian collaborations include Nina ...
"Porin kaupungin tilastollinen vuosikirja 2011" (PDF) (in Finnish). Porin kaupunki. May 2011. p. 8. Archived from the original ( ... "Porin seutu" (in Finnish). Porin seudun kehittämiskeskus Oy POSEK. Retrieved April 29, 2021. Dialogiluento, Kaarina Niskala ja ... J.W., Ruuth (1958). "Kaupungin perustamiskirje". Porin kaupungin historia II (in Finnish). Porin kaupunki. p. 269. Archived ... in Finnish) Porin kaupunki - 1939-1945 Sota ja teollisuus Archived 2012-03-06 at the Wayback Machine (in Finnish). Retrieved 2 ...
"Joel Armia's player profile with his team Porin Ässät" (in Finnish). Porin Ässät. Archived from the original on 7 July 2011. ... Armia would spend three years in Finland, playing with Porin Ässät. During that time, he would have career totals of 55 goals, ...
Porin 2004. Ce jeudi 21 août 1941 ... L'Humanité. Hansen 2014, p. 31. Pigenet 2014. Calvès 1996. Calvès, André (1996). "La ... Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France. AERI. Retrieved 2015-05-21.. ...
Porin 2004. Viet-Depaule 2002, p. 198. Salle Eugène HENAFF. Steinhouse 2001, pp. 28-29. Steinhouse 2001, p. 150. Ross 1982, p. ... Porin, Axel (2004). "Albert Ouzoulias". La Résistance en Ile-de-France. AERI. Retrieved 2015-05-21. Ross, George (1982). ...
Opacity family porins are a family of porins from pathogenic Neisseria. These bacteria possess a repertoire of phase-variable ...
InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.
Porin may refer to: Porin (protein), a transmembrane protein Porin (opera), a Croatian grand opera, first performed in 1897 ... first awarded in 1994 and named after the opera This disambiguation page lists articles associated with the title Porin. If an ... Porin (music award), Croatian music industry award, ...
Outer membrane porin, bacterial (IPR005318). Short name: OM_porin_bac Overlapping homologous superfamilies *Porin domain ... This family contains bacterial outer membrane porins with serine protease activity [PMID: 9636669]. The serine peptidase domain ...
Kätkö esittelee Porin ehkä yhtä vähiten markkinoitua nähtävyyttä. Kesäaikaan läheisyydessä järjestettävät konsertit saattavat ... Porin pirunkirnu (GC37X64) was created by Porilainen on 11/17/2011. Its a Micro size geocache, with difficulty of 2, terrain ... Tarina Porin pirunkirnun synnystä. Muinaisaikaisen perimätiedon mukaan silloin kun hyvä ja paha taistelivat vallasta, maan ... Eräs näistä haaroista asettui juuri tuon Porin pirun syöverin kohdalle. Joen virtaus toi mukanaan runsaasti santaa ja. savea. ...
... Pinne, Marija Umeå University, Faculty of Medicine, Molecular Biology. ... P66, an integrin binding protein, was also determined to be a porin. The oligomeric state of native P66, elucidated by chemical ... In this thesis, three B. burgdorferi proteins, P13, BBA01 and P66, were shown to be porins, and characterized structurally and ... Finally, the biological relevance of two porins, P13 and P66, was demonstrated in a double mutant displaying a stress response ...
The PDB archive contains information about experimentally-determined structures of proteins, nucleic acids, and complex assemblies. As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.
Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis. ... MATRIX PORIN OUTER MEMBRANE PROTEIN F A 340 Escherichia coli Mutation: D113G Gene Name(s): ompF cmlB coa cry tolF b0929 JW0912 ...
The E. coli Porin Proteins OMPF and Maltoporin (LamB Porin) Kristin Flammer 99, Aaron Downs 00, and David Marcey. Contents: I ... Porin Structure and Function: The General Diffusion Pores Matrix Porin III. Maltoporin Monomer Structure IV. Structural and ... Introduction to Porin Structure and Function: The General Diffusion Pores Matrix Porin (OMPF) Although there is little to no ... Most porins form general, non-specific channels that are regulated by environmental changes. A few porins display substrate- ...
Porins are β-barrel outer-membrane proteins through which small solutes and metabolites diffuse that are also exploited during ... Intrinsically disordered protein threads through the bacterial outer-membrane porin OmpF.. Housden NG1, Hopper JT, Lukoyanova N ... Thus, an intrinsically disordered protein can tunnel through the narrow pores of an oligomeric porin to deliver an epitope ... Intrinsically Disordered Protein Threads through the Bacterial Outer Membrane Porin OmpF. Science. ;340(6140):10.1126/science. ...
The Escherichia coli porin OmpG, which acts as an efficient unspecific channel for mono-, di- and trisaccharides, has been ... Projection structure of the monomeric porin OmpG at 6 A resolution J Mol Biol. 2001 Jan 5;305(1):71-7. doi: 10.1006/jmbi. ... The Escherichia coli porin OmpG, which acts as an efficient unspecific channel for mono-, di- and trisaccharides, has been ... unlike most other porins such as OmpF and OmpC, but appears in monomeric form. The size of the barrel is approximately 2.5 nm, ...
Porin antibody [20B12AF2] (ab14734) has been cited in 185 publications. References for Human, Mouse, Rat, Dm in ICC, ICC/IF, IF ...
Outer Membrane Porins Analysis. The outer membrane porins OmpK35 and OmpK36 were analysed by sodium dodecyl sulphate ... Detection of β-Lactamases and Outer Membrane Porins among Klebsiella pneumoniae Strains Isolated in Iran. Ali Hashemi,1 Fatemeh ... Loss of this porin may be one of the factors contributing to antimicrobial resistance among ESBL-producing K. pneumoniae and ... The outer membrane porins such as OmpK35 and OmpK36 were analysed by SDS-PAGE, PCR, and sequencing methods. From 83 K. ...
In PA-2 lysogens, ipeX is transcribed in cis with the phage porin gene.The ipeX sequence located downstream of the nmpC porin ... we have shown that ipeX is synthesized from the phages porin gene promoter as part of the phage porin transcript at the 3′ ... One such alteration in the OmpC porin was an R74C substitution (OmpCR74C, or OmpC1Cys). This mutant porin and its derivative, ... nmpC transcript ensures that the expression of the host ompC porin gene is inhibited only when the phage porin gene is ...
The transmembrane parts of 16 porins of known structure were precisely annotated using Garlic, the membrane protein ... The statistical data were combined with experimental knowledge about porin insertion to prepare the model of porin insertion ... "Annotation of Transmembrane Segments of Experimentally Solved Bacterial Porins and Adhesins." Croatica Chemica Acta 78, br. 2 ( ... "Annotation of Transmembrane Segments of Experimentally Solved Bacterial Porins and Adhesins." Croatica Chemica Acta, vol. 78, ...
Porin antibody - Mitochondrial Loading Control. Validated in WB, ICC/IF and tested in Mouse, Rat, Dog, Human, Zebrafish, ... Anti-VDAC1 / Porin antibody - Mitochondrial Loading Control. See all VDAC1 / Porin primary antibodies. ... Lane 7 : Hela cell lysate with Human VDAC1 / Porin peptide (ab16131) at 1 µg/ml. Lane 8 : A431 cell lysate with Human VDAC1 / ... Porin peptide (ab16131) at 1 µg/ml. Lane 9 : Jurkat cell lysate with Human VDAC1 / Porin peptide (ab16131) at 1 µg/ml. Lane 10 ...
2016 Structure of carbon nanotube porins in lipid bilayers: an In Situ small-angle X-ray scattering (SAXS) study. Nano Lett. 16 ... 2016 Ultrafast proton transport in sub-1-nm diameter carbon nanotube porins. Nat. Nano 11, 639-644. (doi:10.1038/nnano.2016.43) ... a) Carbon nanotube porin synthesis and incorporation into liposomes. The 0.8 nm diameter CNT were sourced from Sigma-Aldrich ( ... 2014 Osmotically-driven transport in carbon nanotube porins. Nano Lett. 14, 7051-7056. (doi:10.1021/nl5034446). ...
porin activity Source: UniProtKB-KW. *voltage-gated anion channel activity Source: GO_Central ,p>Inferred from Biological ... "Biochemical, molecular, and functional characterization of porin isoforms from potato mitochondria.". Heins L., Mentzel H., ... sp,P42055,VDAC1_SOLTU Mitochondrial outer membrane protein porin of 34 kDa OS=Solanum tuberosum OX=4113 PE=1 SV=2 ... Belongs to the eukaryotic mitochondrial porin (TC 1.B.8.1) family. [View classification]Curated ...
Computer model showing the trimeric structure of porin from Rhodobacter capsulatus. Ligand C8E shown in orange. - Stock Image ... Caption: Porin molecule. Computer model showing the trimeric structure of porin from Rhodobacter capsulatus. Ligand C8E shown ... porin, protein, space-fill, space-filled, spacefill, spacefilled, structure, trimer, trimeric ...
Structural and functional alterations of a colicin-resistant mutant of OmpF porin from Escherichia coli. D Jeanteur, T Schirmer ... Structural and functional alterations of a colicin-resistant mutant of OmpF porin from Escherichia coli ... Structural and functional alterations of a colicin-resistant mutant of OmpF porin from Escherichia coli ... Structural and functional alterations of a colicin-resistant mutant of OmpF porin from Escherichia coli ...
... the porins. Some electrophysiological studies find reconstituted porins in a mostly open state, while those done with the patch ... Membrane-derived oligosaccharides (MDOs) promote closing of an E. coli porin channel.. Delcour AH1, Adler J, Kung C, Martinac ... These findings illustrate that the degree of openness of porins can be regulated by compounds naturally found in bacteria. ... We present here current measurements through porins from reconstituted outer membrane, which demonstrate that bacterial ...
... results provide a rationale for the determinants that govern the binding and permeation of zwitterionic antibiotics in porin ... and atomistic biomolecular simulations reveals weak binding events between the β-lactam antibiotic ampicillin and the porin ... The permeation of most antibiotics through the outer membrane of Gram-negative bacteria occurs through porin channels. To ... Therefore, although the binding mode of a β-lactam to the general porin OmpF from E. coli has previously been elucidated31, ...
This strategy allowed us to dissect the role of each porin regardless of the presence/absence of ToxR. We found that porin ... We have demonstrated virulence defects when one porin is substituted for another, suggesting a relationship between porin ... the ToxR-repressed porin OmpT in place of the ToxR-activated porin OmpU has allowed us to dissect the role these porins play in ... V. cholerae strains were genetically manipulated to force a "porin swap," i.e., a toxR+ strain that expresses OmpT in place of ...
Porin specific for oligogalacturonides. Also required for full virulence. ... "The oligogalacturonate-specific porin KdgM of Erwinia chrysanthemi belongs to a new porin family.". Blot N., Berrier C., ... 1.B.35.1.1. the oligogalacturonate-specific porin (kdgm) family. Protocols and materials databases. Structural Biology ... sp,Q934G3,KDGM_DICD3 Oligogalacturonate-specific porin KdgM OS=Dickeya dadantii (strain 3937) GN=kdgM PE=1 SV=1 ...
Porins are proteins that span cell membranes and act as a channel through which specific molecules can diffuse. - Stock Image ... Caption: Sucrose-specific porin, molecular model. Porins are proteins that span cell membranes and act as a channel through ...
Figure 7. OmpF porin trimer. The looping strands of each porin protein bind with the adjacent loop of the next porin (Shown in ... OmpF Porin Regulation OmpF porin functions to regulate osmotic pressure between the cell and its surroundings. Many factors ... OmpF Porin Structure. --Primary Structure The OmpF porin gene contains 1807 nucleotide bases. 1086 of these 1807 nucleotides ... The outer membrane contains groups of three porins called trimers. The OmpF porin is found in the trimer formation in E. Coli. ...
Rockland Anti-VDAC/Porin Polyclonal, Catalog # 600-401-882. Tested in Western Blot (WB), Immunohistochemistry (IHC), ... Outer mitochondrial membrane protein porin 1; Plasmalemmal porin; Porin 31HL; Porin 31HM; PORIN-31-HL; rVDAC1; VD; VDAC-1; VDAC ... Predicted/Observed size: 32 kDa, 32 kDa for VDAC/Porin.. Western Blot of Rabbit anti-VDAC/Porin antibody. Marker: Opal Pre- ... Cite VDAC/Porin Polyclonal Antibody. The following product was used in this experiment: VDAC/Porin Polyclonal Antibody from ...
... in a Klebsiella pneumoniae Clinical Isolate Producing SCO-1 and CTX-M-15 β-Lactamases Together with OmpK35 and OmpK36 Porin ...
Recognizes the porin 31HL protein. Corresponds to mAb 1 in the literature.,biological,biology supply,biology supplies,biology ... Mouse Anti-Human Porin 31HL Monoclonal Antibody, Unconjugated, Clone 89-173/016 from Calbiochem,AVOID FREEZE/THAW CYCLES. ... Mouse Anti-Human Porin 31HL Monoclonal Antibody, Unconjugated, Clone 89-173/016 from Calbiochem. ... Recognizes the porin 31HL protein. Corresponds to mAb 1 in the literature.. ...
... the effect of the neisserial porins on T-B cell interactions and T cell costimulation was examined. Neisserial porins increased ... Neisserial porins induce B lymphocytes to express costimulatory B7-2 molecules and to proliferate.. L M Wetzler, Y Ho, H Reiser ... The neisserial porins are the major protein components of the outer membrane of the pathogenic Neisseria (N. meningitidis and N ... Neisserial porins induce B lymphocytes to express costimulatory B7-2 molecules and to proliferate. ...
  • In this thesis, three B. burgdorferi proteins, P13, BBA01 and P66, were shown to be porins, and characterized structurally and functionally using a combination of biochemical, biophysical and genetic methods. (diva-portal.org)
  • The porin superfamily contains a number of homotrimeric (transmembrane) proteins that form water-filled pores across the outer cell membranes of gram-negative bacteria. (kenyon.edu)
  • Porins are β-barrel outer-membrane proteins through which small solutes and metabolites diffuse that are also exploited during cell death. (nih.gov)
  • Projection maps of two different crystal forms of OmpG at 6 A resolution show that the protein has a beta-barrel structure characteristic for outer membrane proteins, and that it does not form trimers, unlike most other porins such as OmpF and OmpC, but appears in monomeric form. (nih.gov)
  • A special class of Escherichia coli outer membrane proteins (OMPs) called porins forms water-filled channels through which hydrophilic solutes gain access into the bacterial cell ( 27 ). (asm.org)
  • Porins have led the way in providing insights on the structure, regulation, and assembly of membrane proteins. (asm.org)
  • The OmpC and OmpF porin genes are transcriptionally regulated by a classical two-component signal transduction regulatory system consisting of the OmpR and EnvZ proteins ( 12 , 13 ). (asm.org)
  • Porins are proteins that span cell membranes and act as a channel through which specific molecules can diffuse. (sciencephoto.com)
  • Many factors affect OmpF porin regulation, however, one of the more known is through the proteins EnvZ and OmpR. (davidson.edu)
  • 4. The resulting OmpF mRNA undergoes translation and OmpF porin proteins are assembled and inserted into the outer membrane to prevent further osmotic pressure loss (Liu et al. (davidson.edu)
  • Voltage-dependent anion channel (VDAC) proteins are abundant, pore-forming proteins belonging to the eukaryotic mitochondrial porins. (thermofisher.com)
  • Porin channels in Escherichia coli: studies with liposomes reconstituted from purified proteins. (asm.org)
  • Rates of diffusion of uncharged and charged solute molecules through porin channels were determined by using liposomes reconstituted from egg phosphatidylcholine and purified Escherichia coli porins OmpF (protein 1a), OmpC (protein 1b), and PhoE (protein E). All three porin proteins appeared to produce channels of similar size, although the OmpF channel appeared to be 7 to 9% larger than the OmpC and PhoE channels in an equivalent radius. (asm.org)
  • This entry represents both eukaryotic mitochondrial porins and Tom40 proteins. (embl.de)
  • The eukaryotic mitochondrial porins are beta-barrel proteins, composed of between 12 to 16 beta-strands that span the mitochondrial outer membrane. (embl.de)
  • Unlike transfer of many precursor proteins into or across the inner mitochondrial membrane, assembly of the porin is not dependent on an electrical potential across the inner membrane. (uni-muenchen.de)
  • Using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the bilayer lipid membrane (BLM) technique, heat-modifiable porin-like proteins were identified among the OM proteins of marine pseudomonads. (deepdyve.com)
  • The nature of current fluctuations in the BLM and the conductivity of pores formed by these proteins suggest that these isolated porins are not identical in their functional properties. (deepdyve.com)
  • Isolation and characterization of a family of porin proteins from Helicobacter pylori. (asm.org)
  • Two-dimensional gel electrophoresis was used to identify heat-modifiable outer membrane proteins, which were candidates for porins, from Helicobacter pylori membrane preparations. (asm.org)
  • N-terminal amino acid sequence analyses showed a high degree of homology among all four proteins, and it appears that these proteins constitute a family of related porins in H. pylori. (asm.org)
  • Mitochondrial voltage-dependent anion channel (VDAC) proteins, also known as mitochondrial porins, are conserved in eukaryotes from yeast to humans and play key roles in mediating mitochondrial outer membrane permeability to small metabolites, including ATP, ADP, and AMP. (asm.org)
  • We previously recovered the yeast mitochondrial porin Por1 (yVDAC1) from a two-hybrid screen for Snf1-interacting proteins. (asm.org)
  • Mitochondrial outer membrane permeability is conferred by a family of porin proteins. (elsevier.com)
  • Likewise, our previous work has shown that the major Salmonella Typhi (S. Typhi) outer membrane proteins OmpC and OmpF (porins) are highly immunogenic protective antigens that efficiently stimulate innate and adaptive immune responses in the absence of exogenous adjuvants. (readbyqxmd.com)
  • SUMMARY: Porins are pore-forming outer-membrane proteins which serve as a non-specific pathway for the entry of hydrophilic molecules into Gram-negative bacteria. (microbiologyresearch.org)
  • 93 MemProtMD simulations of Beta-Barrel Membrane Proteins: Porins and Relatives in a lipid bilayer at both coarse-grained and atomistic respresentation, including both file download and analysis. (ox.ac.uk)
  • The findings presented in this thesis enhance the atomistic and functional understanding of ion transport processes through bacterial outer membrane porins in particular and various other membrane proteins in general. (jacobs-university.de)
  • Porins are proteins which cross a cellular membrane and act as a pore through which molecules can diffuse. (auto-jaa.fun)
  • Unlike other membrane transport proteins, porins are large enough to allow passive diffusion - i.e. they act as channels which are specific to different types of molecules (Redirected from Takam Mishing Porin Kebang). (auto-jaa.fun)
  • A quantification showed a 60-70% reduction of porin assembly compared with the wild-type mitochondria (Fig. 8 B). Since the levels of all marker proteins analyzed along with the GIP complex are not disturbed in the mutant mitochondria, we conclude that a functional Tom40 is required for the biogenesis of porin. (nih.gov)
  • Selective permeability is ensured by membrane proteins, such as porins, which are attractive pharmacological targets in host pathogen interactions. (ipbs.fr)
  • The following product was used in this experiment: VDAC/Porin Polyclonal Antibody from Thermo Fisher Scientific, catalog # 600-401-882. (thermofisher.com)
  • VDAC/Porin Antibody was prepared from whole rabbit serum produced by repeated immunizations with a synthetic peptide corresponding to an internal region near amino acids 175-200 of Human VDAC1/Porin1. (thermofisher.com)
  • Anti-VDAC/Porin Antibody is directed against human VDAC1/Porin1 protein. (thermofisher.com)
  • Various lysates were subjected to SDS PAGE followed by western blot with 66345-1-Ig (VDAC1/Porin antibody) at dilution of 1:40000 incubated at room temperature for 1.5 hours. (ptglab.com)
  • Immunohistochemical analysis of paraffin-embedded human heart tissue slide using 66345-1-Ig (VDAC1/Porin antibody) at dilution of 1:1000 (under 10x lens). (ptglab.com)
  • Immunohistochemical analysis of paraffin-embedded human heart tissue slide using 66345-1-Ig (VDAC1/Porin antibody) at dilution of 1:1000 (under 40x lens). (ptglab.com)
  • Boster Bio Anti-VDAC/Porin/VDAC1 Antibody catalog # PA1780. (bosterbio.com)
  • Our Boster Quality Guarantee for Anti-VDAC/Porin/VDAC1 Antibody covers its use in the following applications. (bosterbio.com)
  • Here we use high-speed atomic force microscopy (HS-AFM) to show that a novel type of biomimetic channel-carbon nanotube porins (CNTPs)-is also laterally mobile in supported lipid membranes, mimicking biological protein behaviour. (royalsocietypublishing.org)
  • Both outer membranes accommodate channels of the porin family, which are designed for the uptake and exchange of metabolites, including ions and small molecules, such as nucleosides or sugars. (biochemj.org)
  • Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. (nih.gov)
  • Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES. (ucdenver.edu)
  • Reconstitution experiments were performed on lipid bilayer membranes in the presence of purified mitochondrial porin from yeast and of detergent-solubilized mitochondrial outer membranes of a porin-free yeast mutant. (meta.org)
  • The addition of the porin resulted in a strong increase of the membrane conductance, which was caused by the formation of ion-permeable channels in the membranes. (meta.org)
  • We have studied the effect of divalent cations as Ca++ and Ba++ that exert a cross linking together with a screening effect respectively, on the kinetics of incorporation of the mithocondrial porin in bimolecular lipid membranes made with phosphatydilinositol. (unimi.it)
  • In contrast to the kinetics of incorporation of the porin in oxidized cholesterol lipid membranes (4), showing an hyperbolic shape. (unimi.it)
  • Synthetic peptide corresponding to Human VDAC1/ Porin aa 150-250. (abcam.com)
  • VDAC1, also named as VDAC, porin 31HM, porin 31HL and plasmalemmal porin, belongs to the eukaryotic mitochondrial porin family. (ptglab.com)
  • Recombinant full length protein corresponding to Human VDAC1/ Porin. (abcam.co.jp)
  • Nutrients cross this permeability barrier by diffusion through porins. (sigmaaldrich.com)
  • This also indicated that a minimal porin-mediated OM permeability is essential for survival of M. smegmatis. (sigmaaldrich.com)
  • The amount of Msp porin and the OM permeability of the triple porin mutant lacking mspA, mspC and mspD was not altered. (sigmaaldrich.com)
  • The growth rate of M. smegmatis dropped drastically with its porin-mediated OM permeability in contrast to porin mutants of Escherichia coli. (sigmaaldrich.com)
  • The low permeability of this porin channel is a major factor that enhances other types of resistance mechanisms and often creates strong multidrug resistance in this nosocomial pathogen. (ovid.com)
  • As many environmental pathogens causing nosocomial infections appear to have outer membrane protein (OmpA)/OprF homologs as the major porin, efforts to understand the low permeability of these 'slow porins' are important in our fight against these organisms. (ovid.com)
  • Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals. (elsevier.com)
  • Inhibition of the mitochondrial permeability transition pore by cyclosporin A in wild-type hippocampal slices reproduces the electrophysiological phenotype of porin-deficient mice. (elsevier.com)
  • These results demonstrate a dynamic functional role for mitochondrial porins and the permeability transition pore in learning and synaptic plasticity. (elsevier.com)
  • However, whether or not OmpX functions as a porin to modulate the membrane permeability is still unclear. (biomedcentral.com)
  • We concluded that the OM of M. smegmatis represents a permeability barrier for phosphates and that Msp porins are the only OM channels for the diffusion of phosphate in M. smegmatis. (uab.edu)
  • Here, we use the bacterial porin OmpF from E. coli as a model system to gain insight on the control of outer membrane permeability by bacterial porins through the modulation of their open state. (mdpi.com)
  • We have recently reported simple and versatile artificial membrane pore analogues-carbon nanotube porins (CNTPs)-short segments of single-wall carbon nanotubes that can self-insert into the lipid membrane and form a transmembrane pore [ 10 ]. (royalsocietypublishing.org)
  • However, ToxR, independently of TcpP and ToxT, activates and represses transcription of the genes encoding two outer-membrane porins, OmpU and OmpT. (pnas.org)
  • Although genes encoding TcpP, ToxT, CT, and TCP are specifically associated with V. cholerae , ToxR is found in other Vibrio and Photobacterium species and regulates porin expression in these other bacteria as well ( 13 , 14 ). (pnas.org)
  • The sizes of PCR-amplified products from ompF -type genes are different from those of other porin genes (data not shown). (asm.org)
  • Expression levels of efflux and porin genes were mesured by real-time reverse transcription PCR. (jidc.org)
  • However, the regulation of porin genes and its own gene by CRP remains unclear in Y. pestis . (biomedcentral.com)
  • It is likely that Y. pestis OmpR and CRP respectively sense different signals (medium osmolarity, and cellular cAMP levels) to regulate porin genes independently. (biomedcentral.com)
  • Data presented here indicate a remarkable remodeling of the CRP-mediated regulation of porin genes and of its own one between these two bacteria. (biomedcentral.com)
  • Decreased susceptibility to fluoroquinolones could be partly explained by decreased expression of the outer membrane porin genes ompA and ompF with a concomitant increase in the expression of the ciprofloxacin resistance efflux pump gene acrB in Δcrp cells. (readbyqxmd.com)
  • 4 mg l -1 ), 60.5 % (115/190) showed mutation in both porin genes. (cdc.gov)
  • OprF is the major porin of Pseudomonas aeruginosa and allows very slow, nonspecific, diffusion of solutes. (ovid.com)
  • Muderris T, Durmaz R, Ozdem B, Dal T, Unaldı O, Aydogan S, Celikbilek N, Acıkgoz Z (2018) Role of efflux pump and OprD porin expression in carbapenem resistance of Pseudomonas aeruginosa clinical isolates. (jidc.org)
  • Structure of a putative BenF-like porin from Pseudomonas fluorescens Pf-5 at 2.6 A resolution. (ucdenver.edu)
  • The major focus of this thesis is to probe the phosphate selectivity of the OprP porin from the bacterium Pseudomonas aeruginosa. (jacobs-university.de)
  • In response to low extracellular glucose concentration, Pseudomonas aeruginosa induces the expression of the outer membrane carbohydrate-selective OprB porin. (umanitoba.ca)
  • Sucrose-specific porin, molecular model. (sciencephoto.com)
  • In contrast, the recent structures of the mitochondrial porin, also known as VDAC (voltage-dependent anion channel), show an uneven number of 19 β-strands, but a similar molecular architecture. (biochemj.org)
  • The apparent molecular weight of the porin synthesized in homologous or heterologous cell-free systems is the same as that of the mature porin. (uni-muenchen.de)
  • The cell wall porin was purified to homogeneity and had an apparent molecular mass of about 87 kDa on tricine-containing SDS-PAGE. (nih.gov)
  • Further studies should allow the identification of the individual contribution of the single porin channel to the overall bacterial infrared spectrum and of molecular predictive patterns of porin alterations. (spectroscopynow.com)
  • The toxin was found to coincide with a 45 kDa protein possessing an N-terminus sequence indicative of a bacterial outer membrane porin protein together with a high molecular weight carbohydrate which was determined to be lipopolysaccharide (LPS). (unh.edu)
  • Bacon, David John, "Molecular characterization of a cytotoxic porin protein from Campylobacter jejuni and its role in campylobacteriosis" (1997). (unh.edu)
  • The research work reported in this thesis is aimed at understanding ion transport processes, namely ion selectivity and ion conductance, through bacterial outer membrane porins using molecular dynamics simulations. (jacobs-university.de)
  • Recent experimental investigations pointed out how the diffusion of antibiotics through a porin is a molecular-based process: during diffusion the antibiotics interact strongly with the amino acids of the porin. (unica.it)
  • The oligomeric state of native P66, elucidated by chemical cross-linking, indicated that P66 forms trimers, as do the majority of conventional porins. (diva-portal.org)
  • The profound stability of porin trimers is a product of tight monomer interactions. (kenyon.edu)
  • The outer membrane contains groups of three porins called trimers. (davidson.edu)
  • We raised 41 monoclonal antibodies (MAbs) to Salmonella typhimurium OmpD and OmpC porin trimers and monomers. (mysciencework.com)
  • MspA is the major porin of Mycobacterium smegmatis. (sigmaaldrich.com)
  • Isolates without obvious genetic lesions in either major porin gene were further examined by outer membrane protein SDS-PAGE. (cdc.gov)
  • Porin may refer to: Porin (protein), a transmembrane protein Porin (opera), a Croatian grand opera, first performed in 1897 Porin (music award), Croatian music industry award, first awarded in 1994 and named after the opera This disambiguation page lists articles associated with the title Porin. (wikipedia.org)
  • A generally accepted view of the porin assembly pathway is that after the removal of the signal peptide from precursors, mature porin molecules transiently exist in the periplasm as soluble or peripherally membrane-associated, thermolabile intermediates. (asm.org)
  • OmpF porin is a non-specific transport channel that allows for the passive diffusion of small, polar molecules (600-700 Da in size) through the cell's outer membrane. (davidson.edu)
  • Neisserial porins induce B lymphocytes to express costimulatory B7-2 molecules and to proliferate. (rupress.org)
  • However, the OmpF porin channel allowed influx of more solute molecules per unit time than did the equivalent weight of the OmpC porin when the flux was driven by a concentration gradient of the same size. (asm.org)
  • Paper I: In Silico Structure and Sequence Analysis of Bacterial Porins and Specific Diffusion Channels for Hydrophilic Molecules: Conservation, Multimericity and Multifunctionality. (uio.no)
  • The two major porins of Escherichia coli , namely OmpF and OmpC, form non-specific transport channels and allow for the passive diffusion of small, polar molecules (such as water, ions, amino acids, and other nutrients, as well as waste products) across the cell membrane. (biomedcentral.com)
  • The over-expression of OmpX can balance the decreased expression of non-specific porins, OmpF and OmpC, for the exclusion of small harmful molecules. (biomedcentral.com)
  • Moreover, S. Typhi porins induce the expression of costimulatory molecules on antigen-presenting cells through toll-like receptor canonical signaling pathways. (readbyqxmd.com)
  • However, general diffusion porins located in this membrane allow the entry, by simple diffusion, of small molecules and, among them, antibiotics (beta-lactams and fluoroquinolones). (unica.it)
  • This family contains bacterial outer membrane porins with serine protease activity [ PMID: 9636669 ]. (ebi.ac.uk)
  • These findings illustrate that the degree of openness of porins can be regulated by compounds naturally found in bacteria. (nih.gov)
  • The permeation of most antibiotics through the outer membrane of Gram-negative bacteria occurs through porin channels. (nature.com)
  • Outer membrane protein C is a porin that resides in the outer membrane, and it has been identified as an antigenic protein in many bacteria, such as Escherichia coli, Salmonella typhi, Aeromonas hydrophila and Edwardsiella tarda. (readbyqxmd.com)
  • Of the surface components of Gram-negative bacteria, porins exhibit a biological activity similar to that of LPS. (microbiologyresearch.org)
  • Bacteria and mitochondria both have porins but not apparently of common origin. (evolutionnews.org)
  • Strains of bacteria resistant to beta-lactams have shown either a low porin density in the outer membrane, or some mutations at the level of porins affecting their internal size. (unica.it)
  • Transfer in vitro of mitochondrial porin from the cytosolic fraction into the outer membrane of mitochondria could be demonstrated. (uni-muenchen.de)
  • We have used mitochondria from Neurospora crassa and Saccharomyces cerevisiae to analyze the import pathway of porin. (nih.gov)
  • Import of porin into isolated mitochondria in which the outer membrane has been opened is inhibited despite similar levels of Tom20 as in intact mitochondria. (nih.gov)
  • A matrix-destined precursor and the porin precursor compete for the same translocation sites in both normal mitochondria and mitochondria whose surface receptors have been removed, suggesting that both precursors utilize the general import pore. (nih.gov)
  • A) Radiolabeled porin precursor (10 μl reticulocyte lysate per lane) was incubated with isolated yeast mitochondria as indicated (50 μg protein per lane) at 25°C. The mitochondria were reisolated, lysed in digitonin-containing buffer, and subjected to BN-PAGE and digital autoradiography. (nih.gov)
  • The total amount of assembled radiolabeled porin after 30 min in wild-type mitochondria was set to 100% (control). (nih.gov)
  • When the mitochondria were preincubated at 37°C, the assembly of porin in the tom40 mutant mitochondria was similarly reduced compared with wild-type mitochondria. (nih.gov)
  • We then incubated radiolabeled porin with isolated wild-type, tom40-2, and tom40-4 mitochondria and analyzed them by BN-PAGE. (nih.gov)
  • The assembly of porin was inhibited in the mutant mitochondria (Fig. 8 A, lanes 4-9). (nih.gov)
  • The outer membrane porins such as OmpK35 and OmpK36 were analysed by SDS-PAGE, PCR, and sequencing methods. (hindawi.com)
  • Outer membrane porin, OmpK35, was detected in 30 (62.5%) of 48 ESBL-producing isolates while OmpK36 was found in 35 (72.91%) of 48 ESBL-producing isolates. (hindawi.com)
  • Carbapenem resistance in K. pneumoniae is based on various mechanisms that may involve carbapenemase production, upregulation of efflux pumps, or loss of porins, including OmpK35, OmpK36, and OmpK37. (hindawi.com)
  • OmpK35 from Klebsiella pneumoniae is the homologue of Escherichia coli OmpF porin. (asm.org)
  • Klebsiella pneumoniae produces two major porins (OmpK35 and OmpK36) and the quiescent porin OmpK37. (asm.org)
  • Most clinical isolates of K. pneumoniae lacking extended-spectrum β-lactamase (ESBL) express both OmpK35 and OmpK36 porins, while most ESBL-expressing K. pneumoniae clinical isolates produce only OmpK36 ( 9 ). (asm.org)
  • Preliminary results ( 6 ) indicate that OmpK35 allows efficient penetration of cefoxitin, cefotaxime, and carbapenems, but there has been some controversy on the role of this porin in cephalosporin penetration in K. pneumoniae ( 18 ). (asm.org)
  • Recombinants were screened for ompK35 by PCR using primers U681 (5′-CGG TTA CGG CCA GTG GGA ATA-3′) and L1316 (5′-GAC GCA GAC CGA AAT CGA ACT-3′), specific for enterobacterial porins and located 215 and 850 bp downstream of the ompK36 start codon, respectively ( 6 ). (asm.org)
  • The expression of OmpK35 was downregulated in a high-osmolarity culture medium, as occurs with the OmpF-like porins ( 9 ), and OmpK35 reacted with anti-OmpK35 in immunoblot experiments (data not shown). (asm.org)
  • The OmpK35 protein expressed by the E. coli clone was extracted by porin extraction methods based on the trypsin resistance of porins and their strong noncovalent association with the peptidoglycan, and it also retained its heat modifiability. (asm.org)
  • To understand the diversity of porin disruption in Klebsiella pneumoniae, the major outer membrane protein (OMP) porins, OmpK35 and OmpK36, were examined in a set of isolates that did not harbour traditional carbapenem-hydrolysing enzymes, but nevertheless tested non-susceptible to ertapenem. (cdc.gov)
  • In addition, incubation with the neisserial porins increased the T lymphocyte costimulatory ability of B lymphocytes, which was inhibited by anti-B7-2 but not anti-B7-1 monoclonal antibodies. (rupress.org)
  • Structural relatedness of enteric bacterial porins assessed with monoclonal antibodies to Salmonella typhimurium OmpD and OmpC. (mysciencework.com)
  • We have studied how the bacteriocin colicin E9 (ColE9) assembles a cytotoxic translocon at the surface of Escherichia coli that incorporates the trimeric porin OmpF. (nih.gov)
  • Computer model showing the trimeric structure of porin from Rhodobacter capsulatus. (sciencephoto.com)
  • Mitochondrial creatine kinase and mitochondrial outer membrane porin show a direct interaction that is modulated by calcium. (inserm.fr)
  • Porin, also termed the voltage-dependent anion channel, is the most abundant protein of the mitochondrial outer membrane. (nih.gov)
  • The statistical data were combined with experimental knowledge about porin insertion to prepare the model of porin insertion into the outer membrane. (srce.hr)
  • The two classical porins OmpC and OmpF consist of three 16-stranded β barrels, each of which forms a channel that is restricted in the middle due to the inward folding of a loop ( 8 ). (asm.org)
  • Omp32, the strongly anion-selective porin from Comamonas acidovorans, has been crystallized. (uni-konstanz.de)
  • Mitochondrial creatine kinase (MtCK) co-localizes with mitochondrial porin (voltage-dependent anion channel) and adenine nucleotide translocator in mitochondrial contact sites. (inserm.fr)
  • In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. (diva-portal.org)
  • The analysis of the single-channel conductance data in different salt solutions using the Renkin correction factor, and the effect of negative charges on channel conductance suggested that the diameter of the cell wall porin is about 1.4-1.6nm. (nih.gov)
  • The other focus of the thesis is to decipher the ion conductance properties through the OmpF and NanC porins from Escherichia coli. (jacobs-university.de)
  • In case of NanC, an asymmetric distribution of charged residues inside the pore was found to be responsible for an asymmetric conductance property and a weak anion selectivity of the porin. (jacobs-university.de)
  • In addition, mutants of OmpF and NanC have been generated to modify ion conductance properties of these porins. (jacobs-university.de)
  • Yeast porin has a single-channel conductance of 4.2 nS in 1 M KCl. (meta.org)
  • Among a panel of independent V. cholerae rpoE mutants, more than 75% contain suppressor mutations that reduce production of OmpU, V. cholerae's principal outer membrane porin. (harvard.edu)
  • ATR-FTIR spectroscopy proved to reliably distinguish between several E. coli porin mutants with an accuracy not replicated by FTIR in transmission mode (using previously optimized procedures). (spectroscopynow.com)
  • Although we confirm the findings of Fiedler and Rotering, we find that the regulation of OmpF and OmpC expression in mdoA mutants is normal in cells grown on other low- osmolarity media, eliminating the possibility that MDO itself might control porin expression. (princeton.edu)
  • Finally, the biological relevance of two porins, P13 and P66, was demonstrated in a double mutant displaying a stress response as revealed by increased sensitivity to high osmolarity and elevated expression of the B. burgdorferi heat-shock protein HtrA homolog. (diva-portal.org)
  • A novel mechanism of Escherichia coli porin regulation was discovered from multicopy suppressors that permitted growth of cells expressing a mutant OmpC protein in the absence of DegP. (asm.org)
  • This mutant porin and its derivative, OmpC R74C,G154C , or OmpC 2Cys ( 17 ), are the subjects of this work and are further discussed below. (asm.org)
  • Considering the colicin resistance of the mutant, it is inferred that in vivo, colicin N traverses the outer membrane through the porin channel or that the dynamics of the exposed loops are affected in the mutant such that these may impede the binding of the toxin. (pnas.org)
  • Hoenger A, Ghosh R, Schoenenberger CA, Aebi U, Engel A. Direct in situ structural analysis of recombinant outer membrane porins expressed in an OmpA-deficient mutant Escherichia coli strain. (ucdenver.edu)
  • The uptake of phosphate by a mutant lacking the porins MspA and MspC was twofold lower than that by wild-type M. smegmatis. (uab.edu)
  • The characterization of two new mutant alleles of the essential pore protein Tom40 demonstrates that the import of porin also requires a functional Tom40. (nih.gov)
  • A strain of Escherichia coli, selected on the basis of its resistance to colicin N, reveals distinct structural and functional alterations in unspecific OmpF porin. (pnas.org)
  • The OmpF porin is found in the trimer formation in E. Coli . (davidson.edu)
  • OmpF porin functions to regulate osmotic pressure between the cell and its surroundings. (davidson.edu)
  • The OmpF porin gene contains 1807 nucleotide bases. (davidson.edu)
  • OmpF porin contains 340 amino acid residues. (davidson.edu)
  • These 22 amino acids form a precursor sequence to the OmpF porin. (davidson.edu)
  • They are eventually cleaved off to form OmpF porin (Inokuchi et al, 1982). (davidson.edu)
  • This precursor form of OmpF porin contains 362 amino acids. (davidson.edu)
  • They are cleaved from the amino acid sequence as the precursor is being converted to OmpF porin (Inokuchi et al, 1982). (davidson.edu)
  • The amino acid sequence provides the basis for the formation of the b- barrel channel of OmpF porin. (davidson.edu)
  • Cartoon structures of OmpF porin have been deduced by x-ray crystallography. (davidson.edu)
  • Using a recent algorithm able to accelerate all-atom MD simulations, the metadynamics, we were able to follow the diffusion of some different antibiotics through the OmpF porin. (unica.it)
  • ipeX was localized within an untranslated region of 247 base pairs between the stop codon of nmpC -a remnant porin gene from the cryptic phage qsr ′ (DLP12) genome-and its predicted Rho-independent transcriptional terminator. (asm.org)
  • The promoter region of the oprB gene was cloned into a lacZ transcriptional fusion vector, and the construct was mobilized into P. aeruginosa OprB-deficient strain, WW100, to evaluate additional environmental factors that influence OprB porin gene expression. (umanitoba.ca)
  • Earlier we have reported the extreme thermal stability of porin from Paracoccus denitrificans reconstituted into liposomes. (uni-konstanz.de)
  • Our results show that a mixed lipid system (non-uniform bilayer) optimizes the thermal stability of porin as compared to the porin in pure lipids (uniform bilayer) or detergent micelles. (uni-konstanz.de)
  • Annotation of Transmembrane Segments of Experimentally Solved Bacterial Porins and Adhesins', Croatica Chemica Acta , 78(2), str. (srce.hr)
  • The transmembrane parts of 16 porins of known structure were precisely annotated using Garlic, the membrane protein visualization program. (srce.hr)
  • We formulate an algorithm to predict the transmembrane beta strands in the family of bacterial porins based on the conformational parameters and surrounding hydrophobicities of amino acid residues. (semanticscholar.org)
  • DI-fusion Characterization of a porin channel in the endosymbiont of. (ac.be)
  • Characterization of a porin channel in the endosymbiont of the trypanosomatid protozoan Crithidia deanei. (ac.be)
  • Using the 3.2 Å structure of the shorter L6 variant in the open state, we engineered a minimal porin (220 amino acids), where all remaining extramembranous loops were truncated. (hud.ac.uk)
  • Salmonella presents its resistance by substituting amino acids within the topoisomerase subunits, overexpression of multidrug efflux pumps, or decreasing the expression of outer membrane porins. (intechopen.com)
  • To determine the role of ToxR-dependent porin regulation in V. cholerae pathogenesis, the ToxR-activated ompU promoter was used to drive ompT transcription in a strain lacking OmpU. (pnas.org)
  • Our results indicate that ToxR-dependent modulation of the outer membrane porins OmpU and OmpT is critical for V. cholerae bile resistance, virulence factor expression, and intestinal colonization. (pnas.org)
  • ToxR, however, independently of the transcriptional activators TcpP and ToxT, modulates expression of two outer membrane porins, OmpU and OmpT ( 8 - 10 ). (pnas.org)
  • Thus, ToxR-dependent modulation of porins apparently preceded, and possibly contributed to, the evolution of V. cholerae as a human pathogen, but little is known about the potential role of OmpU and OmpT in V. cholerae pathogenesis. (pnas.org)
  • V. cholerae strains were genetically manipulated to force a "porin swap," i.e., a toxR + strain that expresses OmpT in place of OmpU and a toxR − strain that expresses OmpU in place of OmpT. (pnas.org)
  • The Escherichia coli porin OmpG, which acts as an efficient unspecific channel for mono-, di- and trisaccharides, has been purified and crystallized in two dimensions. (nih.gov)
  • Membrane-derived oligosaccharides (MDO's) promote closing of an E. coli porin channel. (nih.gov)
  • This interaction was independent of the immobilized binding partner (porin reconstituted in liposomes or MtCK) or the analyzed isoform (chicken sarcomeric MtCK or human ubiquitous MtCK, human recombinant porin, or purified bovine porin). (inserm.fr)
  • Top: Schematic showing CNT porin preparation and incorporation into liposomes. (lbl.gov)
  • There also have been reports of some unusual and less well-understood mechanisms of porin regulation. (asm.org)
  • Another fascinating but even less understood example of porin regulation involves the lysogenization of E. coli K-12 cells by the PA-2 phage ( 28 ). (asm.org)
  • Because mitochondrial porins have significant roles in diverse cellular processes including regulation of mitochondrial ATP and calcium flux, we sought to determine their importance in learning and synaptic plasticity in mice. (elsevier.com)
  • Our data suggest that a certain minimal ionic strength in the periplasm is needed for normal porin regulation. (princeton.edu)
  • Here, the lysogenization event leads to the expression of a phage-encoded porin, Lc, and the inhibition of the host's OmpC porin. (asm.org)
  • The work conducted in this study will shed light on how phage porin expression regulates that of ompC . (asm.org)
  • Neisserial porins increased the surface expression of the costimulatory ligand B7-2 (CD86) but did not affect the expression of B7-1 (CD80). (rupress.org)
  • Herein, both transmission Fourier-transform infrared (FTIR) and attenuated total reflectance (ATR)-FTIR spectroscopy are used to analyse E. coli strains that differ solely in their porin expression profile. (spectroscopynow.com)
  • Growth temperature, pH of the growth medium, salicylate concentration, and carbohydrate source were found to differentially influence porin expression. (umanitoba.ca)
  • Moreover, the porin precursor can be cross-linked to Tom20, Tom22, and Tom40 on its import pathway. (nih.gov)
  • The outer membrane of Escherichia coli is a diffusion barrier for macromolecules, but allows the passage of small hydrophilic solutes through non-specific channels, the porins. (nih.gov)