The etiologic agent of CHOLERA.
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.
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.
Proteins found in any species of bacterium.
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.
Proteins isolated from the outer membrane of Gram-negative bacteria.
Gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.
Cyclic AMIDES formed from aminocarboxylic acids by the elimination of water. Lactims are the enol forms of lactams.
Infections with bacteria of the genus KLEBSIELLA.
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.
Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
Preparatory activities in ROOT CANAL THERAPY by partial or complete extirpation of diseased pulp, cleaning and sterilization of the empty canal, enlarging and shaping the canal to receive the sealing material. The cavity may be prepared by mechanical, sonic, chemical, or other means. (From Dorland, 28th ed, p1700)
A treatment modality in endodontics concerned with the therapy of diseases of the dental pulp. For preparatory procedures, ROOT CANAL PREPARATION is available.
Chemicals used mainly to disinfect root canals after pulpectomy and before obturation. The major ones are camphorated monochlorophenol, EDTA, formocresol, hydrogen peroxide, metacresylacetate, and sodium hypochlorite. Root canal irrigants include also rinsing solutions of distilled water, sodium chloride, etc.
Phase of endodontic treatment in which a root canal system that has been cleaned is filled through use of special materials and techniques in order to prevent reinfection.
The space in a tooth bounded by the dentin and containing the dental pulp. The portion of the cavity within the crown of the tooth is the pulp chamber; the portion within the root is the pulp canal or root canal.
Materials placed inside a root canal for the purpose of obturating or sealing it. The materials may be gutta-percha, silver cones, paste mixtures, or other substances. (Dorland, 28th ed, p631 & Boucher's Clinical Dental Terminology, 4th ed, p187)
The narrow passage way that conducts the sound collected by the EAR AURICLE to the TYMPANIC MEMBRANE.
Bacteria which retain the crystal violet stain when treated by Gram's method.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.
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.
Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.
Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Porin-like barrel structures are encoded by as many as 2-3% of the genes in Gram-negative bacteria. In many cases, the strands ... Porins and other membrane proteins containing beta barrels reverse this pattern, with hydrophobic residues oriented toward the ... Sixteen- or eighteen-stranded up-and-down beta barrel structures occur in porins, which function as transporters for ions and ... Such structures appear in the outer membranes of gram-negative bacteria, chloroplasts, and mitochondria. The central pore of ...
... s (or LamB porins) are bacterial outer membrane proteins of the porin family. Maltoporin forms a trimeric structure ... which facilitates the diffusion of maltodextrins across the outer membrane of Gram-negative bacteria. The membrane channel is ...
General bacterial porin family, known as trimeric porins (n=16,S=20) ... Beta-barrel proteins are so far found only in outer membranes of gram-negative bacteria, cell walls of gram-positive bacteria, ... Outer membrane protein G porin family (n=14,S=16). Note: n and S are, respectively, the number of beta-strands and the "shear ... MspA porin (octamer, n=S=16) and α-hemolysin (heptamer n=S=14) . These proteins are secreted. ...
The size and number of porins are different in different bacteria. As a result of the two factors-size of penicillin and porin- ... In bacteria like Pseudomonas aeruginosa, there is reduced number of porins; whereas in bacteria like Enterobacter species, ... In contrast, large vancomycin can not pass through porins and is thus ineffective for Gram-negative bacteria. ... Resistance in Gram-negative bacteria is due to mutational variations in the structure and number of porins. ...
Changes in the porin protein hinder the diffusion of carbapenem and other antibiotics into the periplasm. Bacteria that express ... The loss of OmpK36 porins can be attributed to point mutations that result in premature termination of translation, resulting ... No new drugs for the bacteria are in development and the bacteria's rapid adaptation to new drugs makes investment in their ... Changes within the porin protein gene cause a frameshift, altering the porin structure and function. ...
The plasmids containing TEM-1 could be passed from bacterium to bacterium via conjugation Quinolones are a class of synthetic ... The cell wall of N. gonorrhoeae contains porins which are holes within the cell wall in which some molecules are able to ... Resistance appears to be acquired through porin-related mechanisms, much like the cephalosporin resistance mechanism. This ... The bacteria was first identified in 1879. In the 1940s effective treatment with penicillin became available, but by the 1970s ...
October 1994). "Porins from plants. Molecular cloning and functional characterization of two new members of the porin family". ... Some mitochondria and some plastids contain single circular DNA molecules that are similar to the DNA of bacteria both in size ... Transport proteins called porins are found in the outer membranes of mitochondria and chloroplasts and are also found in ... New mitochondria and plastids are formed only through binary fission, the form of cell division used by bacteria and archaea. ...
... (OmpG) is a porin, a channel proteins in the outer membrane of Gram-negative bacteria. Escherichia ... The central pore of OmpG is wider than other E. coli porins and it is speculated that it may form a non-specific channel for ... Subbarao GV, van den Berg B (July 2006). "Crystal structure of the monomeric porin OmpG". J. Mol. Biol. 360 (4): 750-9. doi: ... coli OmpG forms a 14-stranded beta-barrel and in contrast to most porins, appears to function as a monomer. ...
Porins exist in the outer membrane, which act like pores for particular molecules ... Gram-negative bacteria only: Bacterial outer membrane *Porin. *Lipopolysaccharide. *Periplasmic space. *Mycobacteria only: ... The gram-negative bacteria include the model organism Escherichia coli, as well as many pathogenic bacteria, such as ... Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial ...
... due in part to their use of porins that can adopt a conformation having a very restricted entry channel. Further, the porin ... These bacteria exhibit an unusually high level of intrinsic resistance to antibiotics due to their expression of a wide range ... Antibiotic molecules that successfully traverse the porin channels may be removed by efflux pumps. Downregulation of the porin ... The spectrum of activity of the carbapenems against gram-positive bacteria is fairly broad, but not as exceptionally so as in ...
In comparison, it is easier to penetrate the cell wall of gram-positive bacteria than the cell wall of gram-negative bacteria. ... It is thought that the positive charge orients the drug molecule to the entrance of the porin channel. Currently there are only ... Particles get through the outer membrane through water-filled channels, or porins, which are trans membrane proteins. During ... gram-positive bacteria to being more effective against gram-negative bacteria and less effective against gram-positive bacteria ...
Porins were first discovered in gram-negative bacteria, but gram-positive bacteria with both types of porins have been found. ... Porins are water-filled pores and channels found in the membranes of bacteria and eukaryotes. Porin-like channels have also ... Porins have threshold sizes of transportable molecules that depend on the type of bacteria and porin. Generally, only ... The Omp50 Porin (Omp50 Porin) Family 1.B.61 - The Delta-Proteobacterial Porin (Delta-Porin) Family 1.B.62 - The Putative ...
These proteins are structurally different from the typical porins located in the outer membrane of Gram-negative bacteria. For ... Mycobacterial porins are a group of transmembrane beta-barrel proteins produced by mycobacteria, which allow hydrophilic ... Mycobacterial porins--new channel proteins in unique outer membranes, by Michael Niederweis, Molecular Microbiology, 2003 ... nutrients to enter the bacterium. They are located in the cell envelope of Gram-positive mycobacteria in a thick layer of ...
Oligogalacturonate-specific porins (KdgM) are a family of outer bacterial membrane proteins from Dickeya dadantii. The ... phytopathogenic Gram-negative bacteria D. dadantii secretes pectinases, which are able to degrade the pectic polymers of plant ... "The oligogalacturonate-specific porin KdgM of Erwinia chrysanthemi belongs to a new porin family". J. Biol. Chem. 277 (10): ... KdgM behaves like a voltage-dependent porin that is slightly selective for anions and that exhibits fast block in the presence ...
October 1994). "Porins from plants. Molecular cloning and functional characterization of two new members of the porin family". ... Survivors have x-bacteria living in their cytoplasm [IV] Antibiotics kill x-bacteria: host amoebae die as now dependent on x- ... There are many lines of evidence that mitochondria and plastids including chloroplasts arose from bacteria.[48][49][50][51][52] ... New mitochondria and plastids are formed only through binary fission, the form of cell division used by bacteria and archaea.[ ...
... family 1.B.34 Corynebacterial porins 1.B.35 Oligogalacturonate-specific porin (KdgM) family 1.B.39 Bacterial porin, OmpW (OmpW ... Bacterial photosynthetic reaction centres and photosystems I and II Light harvesting complexes from bacteria and chloroplasts 4 ... Omp50 Porin) family 1.B.61 Delta-proteobacterial porin (Delta-porin) family 1.B.62 Putative bacterial porin (PBP) family 1.B.66 ... family 1.B.3 Sugar porin (SP) family 1.B.4 Brucella-Rhizobium porin (BRP) family 1.B.5 Pseudomonas OprP porin (POP) family 1.B. ...
General bacterial porins are a family of porin proteins from the outer membranes of Gram-negative bacteria. The porins act as ... General bacterial porin family belongs to Porin Superfamily I. The homologous families Sugar Porin(SP) family and Rhodobacter ... It has been shown that a number of porins are evolutionarily related. Porins are composed of β-strands, which are, in general, ... are homologous in structure and function to General bacterial porin family. One such family is The Sugar Porin (SP) Family. ( ...
Among Gram-negative bacteria, the emergence of resistance to extended-spectrum cephalosporins has been a major concern. It ... Several reports have documented failure of cephamycin therapy as a result of resistance due to porin loss. Some patients have ... in strains with loss of outer membrane porins, provide resistance to carbapenems. Members of this family commonly express β- ... AmpC β-lactamases (also termed class C or group 1) are typically encoded on the chromosome of many Gram-negative bacteria ...
"Porins from marine bacteria of the genus Pseudoalteromonas (Gammaproteobacteria: Pseudoalteromonadaceae), Russian Journal of ... Patch-Clamp Experiments with Porin Extracted from Marine Bacterium (Photobacterium profundum Strain SS9) and Reconstituted in ... Porins from marine bacteria of the genus Pseudoalteromonas (Gammaproteobacteria: Pseudoalteromonadaceae). Porins from marine ... Porins from marine bacteria of the genus Pseudoalteromonas (Gammaproteobacteria: Pseudoalteromonadaceae). Novikova, O.; ...
... reveals weak binding events between the β-lactam antibiotic ampicillin and the porin PorB from the pathogenic bacterium ... To design drugs with increased activity against Gram-negative bacteria in the face of the antibiotic resistance crisis, the ... results provide a rationale for the determinants that govern the binding and permeation of zwitterionic antibiotics in porin ... The permeation of most antibiotics through the outer membrane of Gram-negative bacteria occurs through porin channels. ...
This family of proteins is found in bacteria. Proteins in this family are typically between 655 and 722 amino acids in length. ... These sequences are putative porins.. Contributing signatures. Signatures from InterPro member databases are used to construct ...
... porins are an absolute necessity for the survival of this bacterium. To date, the only porins defined for the order ... Gram-negative bacteria generally have porins spanning their outer membranes. These proteins enable the transport of hydrophilic ... Approximately 50% of isolated bacteria were strongly labeled with anti-rP51. This labeling was noted in bacteria ranging in ... The results showed that P51 has prominent porin activity, whereas Nsp3 does not have significant porin activity. ...
Porins were first discovered in gram-negative bacteria, but gram-positive bacteria with both types of porins have been found. ... Porins are water-filled pores and channels found in the membranes of bacteria and eukaryotes. Porin-like channels have also ... Porins have threshold sizes of transportable molecules that depend on the type of bacteria and porin. Generally, only ... The Omp50 Porin (Omp50 Porin) Family 1.B.61 - The Delta-Proteobacterial Porin (Delta-Porin) Family 1.B.62 - The Putative ...
are the most variable regions among porins. This variability may serve to protect bacteria from infection. A number of surface ... 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 ...
ToxR is found in other Vibrio and Photobacterium species and regulates porin expression in these other bacteria as well (13, 14 ... the ToxR-repressed porin OmpT in place of the ToxR-activated porin OmpU has allowed us to dissect the role these porins play in ... Bacteria added and recovered were quantitated by plate counts, and adherence is expressed as the percent of bacteria adhered ... This strategy allowed us to dissect the role of each porin regardless of the presence/absence of ToxR. We found that porin ...
Like other intestinal bacteria (37), V. choleraemust persist in an environment that is full of bile salts, where porin ... OM porins of gram-negative bacteria, such as OmpU and OmpT, function primarily as channels for entry and exit of hydrophilic, ... The OmpF porin, expressed in growth conditions of low osmolarity, is speculated to be beneficial when the bacteria are outside ... However, porin activity is reportedly absent for OmpV (4) and OmpX (7). It is probable that additional porin activities will be ...
... revealed that root canals are a haven for disease-producing bacteria that alter your DNA and RNA. ... revealed that root canals are a haven for disease-producing bacteria that alter your DNA and RNA. ... These bacteria, the porin producers, have a very high appetite for iron, and hemoglobin furnishes a never ending supply. Once a ... How tiring can bacteria be? One group certainly can contribute. They are called "porins." Few doctors and even fewer humans ...
... revealed that root canals are a haven for disease-producing bacteria that alter your DNA and RNA. ... These bacteria, the porin producers, have a very high appetite for iron, and hemoglobin furnishes a never ending supply. Once a ... How tiring can bacteria be? One group certainly can contribute. They are called "porins." Few doctors and even fewer humans ... meaning they explode the bacteria, causing even more grief for your immune system. Instead of having one bacterium to destroy, ...
These findings illustrate that the degree of openness of porins can be regulated by compounds naturally found in bacteria. ... 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 ... We present here current measurements through porins from reconstituted outer membrane, which demonstrate that bacterial ...
Gram-negative bacteria are protected by an outer membrane in which trimeric channels, the porins, facilitate the passage of ... Voltage and pH-induced channel closure of porin OmpF visualized by atomic force microscopy.. Müller DJ1, Engel A. ... extracellular loops have now been visualized by atomic force microscopy of two-dimensional crystals of Escherichia coli porin ...
Porins exist in the outer membrane, which act like pores for particular molecules ... Gram-negative bacteria only: Bacterial outer membrane *Porin. *Lipopolysaccharide. *Periplasmic space. *Mycobacteria only: ... The gram-negative bacteria include the model organism Escherichia coli, as well as many pathogenic bacteria, such as ... Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial ...
General bacterial porin family, known as trimeric porins (n=16,S=20) ... Beta-barrel proteins are so far found only in outer membranes of gram-negative bacteria, cell walls of gram-positive bacteria, ... Outer membrane protein G porin family (n=14,S=16). Note: n and S are, respectively, the number of beta-strands and the "shear ... MspA porin (octamer, n=S=16) and α-hemolysin (heptamer n=S=14) . These proteins are secreted. ...
In bacteria, the structure of the outer membrane porin protein family of β-barrels is generally characterized by an even number ... Porins in prokaryotes and eukaryotes: common themes and variations Message Subject (Your Name) has forwarded a page to you from ... Porins in prokaryotes and eukaryotes: common themes and variations. Kornelius Zeth, Marcus Thein ... Gram-negative bacteria and mitochondria are both covered by two distinct biological membranes. These membrane systems have been ...
Identification and characterization of a new porin gene of Klebsiella pneumoniae: its role in β-lactam antibiotic resistance. J ... In vitro activities of ertapenem (MK-0826) against recent clinical bacteria collected in Europe and Australia. Antimicrob. ... Role of β-Lactamases and Porins in Resistance to Ertapenem and Other β-Lactams in Klebsiella pneumoniae. George A. Jacoby, ... Plasmid pSHA25K had the greater effect (Table 2). Porin loss was thus clearly involved in mutations to enhanced ertapenem ...
The last category clearly included the mspA and mspA-mspC porin mutants, MN01 and ML10 (Fig. 2B). MspA is the main porin, ... Preventing drug access to targets: cell surface permeability barriers and active efflux in bacteria. Semin. Cell Dev. Biol.12: ... The porin-mediated influx of nutrients was shown to be a major determinant of the growth rates of M. smegmatis and ... Since defects in porin activity also dramatically increased the resistance of M. chelonae to drugs, there is thus some concern ...
Smit J, Nikaido H (1978) Outer membrane of Gram-negative bacteria. XVIII. Electron microscopic studies on porin insertion sites ... Nikaido H (1983) Proteins forming large channels from bacterial and mitochondrial outer membranes: porins and phage lambda ... Benz R (1985) Porin from bacterial and mitochondrial outer membranes. CRC Critical Reviews in Biochemistry 19:145-190PubMed ... Nikaido H, Nakae T (1979) The outer membrane of Gram-negative bacteria. Adv Microb Physiol 20:163-250PubMedGoogle Scholar ...
... strictly aerobic bacterium Nocardia farcinica. The cell wall porin was purified to homogeneity and had an apparent molecular ... The cell wall porins of these members of the order Actinomycetales share common features because they form large and water- ... The cell wall porin was purified to homogeneity and had an apparent molecular mass of about 87 kDa on tricine-containing SDS- ... The cell wall porin of Nocardia farcinica: biochemical identification of the channel-forming protein and biophysical ...
These porin-type proteins are found in the outer membranes of Gram-negative bacteria, mitochondria, plastids and possibly acid- ... β-Barrel Porins. Description:. These proteins form transmembrane pores that usually allow the energy independent passage of ... Evidence has been presented showing that the CsgA curli subunit is exported across the outer membranes of enteric bacteria via ... CsgG forms oligomeric pores in the outer membranes of enteric bacteria. Evidence has been presented showing that the CsgA curli ...
  • 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 pore-forming P-1 and P-2 proteins with molecular masses of 43 and 39 kDa, respectively, were obtained from the marine bacterium P. haloplanktis. (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)
  • This family of proteins is found in bacteria. (ebi.ac.uk)
  • Immunofluorescence labeling not only confirmed surface exposure of these proteins but also showed rosary-like circumferential labeling with anti-P51 for the majority of bacteria and polar to diffuse punctate labeling with anti-Nsp3 for a minority of bacteria. (asm.org)
  • showing new sets of proteins evolved as major surface proteins for Neorickettsia and the first identification of a porin for the genus Neorickettsia . (asm.org)
  • To date, the only porins defined for the order Rickettsiales are major outer membrane proteins of Anaplasma phagocytophilum named P44s ( 22 ) and OMP-1F and P28 in Ehrlichia chaffeensis ( 26 ). (asm.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)
  • ToxR also regulates expression of OM proteins, potentially porins, in other Vibrio and/or Photobacterium species, including V. parahaemolyticus, V. fluvialis, V. mimicus , and Photobacterium profundum ( 23 , 43 , 58 ). (asm.org)
  • [5] Beta-barrel proteins are so far found only in outer membranes of gram-negative bacteria , cell walls of gram-positive bacteria , outer membranes of mitochondria and chloroplasts , or can be secreted as pore-forming toxins . (wikipedia.org)
  • Porins are beta barrel proteins that cross a cellular membrane and act as a pore, through which molecules can diffuse. (wikipedia.org)
  • Unlike other membrane transport proteins, porins are large enough to allow passive diffusion, i.e., they act as channels that are specific to different types of molecules. (wikipedia.org)
  • Amino group-containing compounds susceptible to binding GTA at the surface of RGM include surface-exposed proteins-among which are porins-and glycopeptidolipids. (asm.org)
  • Instead, such mutations consistently reduce or eliminate the function of transport proteins or porins, protein binding affinities, enzyme activities, the proton motive force, or regulatory control systems. (trueorigin.org)
  • They had a drastic reduction in the amount of the major porin but with an apparently conserved normal structure (size and immunogenicity), together with overproduction of two known outer membrane proteins, OmpX and LamB (8). (kenyon.edu)
  • Which of the following statements correctly distinguishes transporters (carrier proteins) from porins and ion channels? (studyblue.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)
  • According to CD data, the porin samples under investigation represent β-sheet proteins. (chemweb.com)
  • Prediction of the structures of multiple SlpA proteins from different radioresistant bacteria using Phyre2 server. (intechopen.com)
  • Bacterial invasion was observed only for strains carrying the P.IA subtype of porin, which is typically associated with the development of disseminated neisserial disease, and did not require opacity outer membrane proteins, previously recognized as gonococcal invasins. (rupress.org)
  • 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)
  • Voltage and pH-dependent conformational changes of these extracellular loops have now been visualized by atomic force microscopy of two-dimensional crystals of Escherichia coli porin OmpF. (nih.gov)
  • The gram-negative bacteria include the model organism Escherichia coli , as well as many pathogenic bacteria , such as Pseudomonas aeruginosa , Neisseria gonorrhoeae , Chlamydia trachomatis , and Yersinia pestis . (wikipedia.org)
  • In addition, an intriguing brief study reported that an unknown volatile compound produced by Escherichia coli could increase resistance to ampicillin and tetracycline antibiotics in physically separated E. coli recipient bacteria ( Heal and Parsons, 2002 ). (wiley.com)
  • Computer model showing a part of the secondary structure of a molecule of outer membrane protein A from Escherichia coli (E. coli) bacteria. (sciencephoto.com)
  • 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)
  • Subsequently, however, resistance has emerged in bacteria such as Campylobacter jejuni , Escherichia coli , and Neisseria gonorrhoeae , in which multiple mutations are required to generate clinically important resistance. (cdc.gov)
  • However, ToxR, independently of TcpP and ToxT, activates and represses transcription of the genes encoding two outer-membrane porins, OmpU and OmpT. (pnas.org)
  • 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)
  • ToxR, the transmembrane regulatory protein required for expression of virulence factors in the human diarrheal pathogen Vibrio cholerae , directly activates and represses the transcription of two outer membrane porins, OmpU and OmpT, respectively. (asm.org)
  • In an attempt to dissect the role of the OmpU and OmpT porins in viability and virulence factor expression, in-frame chromosomal deletions were constructed in the coding sequences of ompU and ompT of V. cholerae . (asm.org)
  • However, the Δ ompU2 strain was deficient for growth in deoxycholate compared to wild-type, Δ ompT , and Δ ompU2 Δ ompT strains, reinforcing a positive role for the OmpU porin and a negative role for the OmpT porin in V. cholerae resistance to anionic detergents. (asm.org)
  • The ancestral role of ToxR appears to be as a modulator of outer membrane (OM) porins, because ToxR, independently of TcpP and ToxT, activates and represses transcription of two genes encoding major OM porins, OmpU and OmpT, respectively ( 8 , 31 ). (asm.org)
  • Vibrio cholerae, the causative agent of cholera, has two major porins, OmpU and OmpT, for which no structural information is available despite their importance for the bacterium. (rcsb.org)
  • While similar overall to other general porins, the channels of OmpU and OmpT have unusual constrictions that create narrower barriers for small-molecule permeation and change the internal electric fields of the channels. (rcsb.org)
  • OMPF ( o uter m embrane p rotein f ) is among the most general E. coli porins and is, therefore, used as a reference point in discussing the structures of more specific porins such as maltoporin. (kenyon.edu)
  • Membrane-derived oligosaccharides (MDO's) promote closing of an E. coli porin channel. (nih.gov)
  • This protein is a porin found in the outer membranes of gram-negative bacteria like E. coli. (sciencephoto.com)
  • Although the CRP of Y. pestis shows a very high homology to that of E. coli , and the consensus DNA sequence recognized by CRP is shared by the two bacteria, the Y. pestis CRP can recognize the promoters of ompC , F , and X directly rather than that of its own gene, which is different from the relevant regulatory circuit of E. coli . (biomedcentral.com)
  • The OmpF porin is found in the trimer formation in E. Coli . (davidson.edu)
  • Zwei humane Isoformen des mitochondrialen Porins wurden in E. coli kloniert und exprimiert. (tum.de)
  • Voltage and pH-induced channel closure of porin OmpF visualized by atomic force microscopy. (nih.gov)
  • 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)
  • 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)
  • 1995). OmpF porins are found in a trimer formation within the outer cell membrane. (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)
  • The influence of cultivation conditions of pseudotuberculosis bacteria on the spatial structure and the functional activity of nonspecific OmpF-like porin was studied by means of optical spectroscopy, scanning microcalorimetry, and bilayer lipid membrane technique. (chemweb.com)
  • 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)
  • Vibrio cholerae , a motile gram-negative bacterium, lives primarily in aquatic environments. (asm.org)
  • 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 ). (asm.org)
  • The outer membrane porins such as OmpK35 and OmpK36 were analysed by SDS-PAGE, PCR, and sequencing methods. (hindawi.com)
  • KPC-1 is a known carbapenemase ( 14 ) and was encoded by a multicopy plasmid, while group 1 enzymes have been reported to express carbapenem resistance in strains lacking outer membrane porins ( 3 , 10 ). (asm.org)
  • Both strains showed a porin pattern different from that of a susceptible strain. (kenyon.edu)
  • Selective porins are smaller than general porins, and have specificities for chemical species. (wikipedia.org)
  • Along with cell shape, gram-staining is a rapid diagnostic tool and once was used to group species at the subdivision of Bacteria. (wikipedia.org)
  • The epidermis of fish is covered with a layer of mucus, which contributes to the defence of the species against parasites, bacteria and fungi. (portlandpress.com)
  • As we approach the halfway point of the second decade of fluoroquinolone use, resistance has already emerged in some species of bacteria and some clinical settings. (cdc.gov)
  • Some commonly detected carbapenemases are Klebsiella pneumoniae carbapenemase(KPC), New Delhi metallo- β -lactamase-1 (NDM-1), and OXA-48-type enzymes whose respective genes are located on plasmids that enable their transfer between different gram-negative bacteria species [ 2 ]. (hindawi.com)
  • 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 specific amino acids in the channel determine the specificity of the porin to different molecules. (wikipedia.org)
  • Porins are primarily involved in passively transporting hydrophilic molecules of various sizes and charges across the membrane. (wikipedia.org)
  • Porins have threshold sizes of transportable molecules that depend on the type of bacteria and porin. (wikipedia.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)
  • Bacteria produce and sense a previously unsuspected diversity of small molecules used as chemical cues or signals to adapt to changing environments ( Straight and Kolter, 2009 ). (wiley.com)
  • I went from animals to cells to bacteria, from bacteria to molecules, from molecules to electrons. (ncl.ac.uk)
  • 1000 Da) molecules across the outer membranes of bacteria and organelles with variable degrees of selectivity. (tcdb.org)
  • The outer membranes (OM) of many Gram-negative bacteria contain general porins, which form nonspecific, large-diameter channels for the diffusional uptake of small molecules required for cell growth and function. (rcsb.org)
  • General porins have no substrate specificities, though some exhibit slight preferences for anions or cations. (wikipedia.org)
  • usually 14, 16 or 18 strands are observed forming the bacterial porin barrel wall. (biochemj.org)
  • To design drugs with increased activity against Gram-negative bacteria in the face of the antibiotic resistance crisis, the strict constraints on the physicochemical properties of the permeants imposed by these channels must be better understood. (nature.com)
  • Because of the significant role played by the mycobacterial outer membrane in drug susceptibility ( 3 , 12 ) and host-pathogen interactions ( 5 ), there is thus some concern that the widespread use of GTA in clinical settings selects for resistant populations of bacteria, with possible consequences on antibiotic resistance and pathogenicity. (asm.org)
  • Here we report that exposure to gaseous ammonia released from stationary-phase bacterial cultures modifies the antibiotic resistance spectrum of all tested Gram-negative and Gram-positive bacteria. (wiley.com)
  • In particular, when co-administered as an adjuvant, the antimicrobial peptide glycine-leucine-amide caused up to 30-fold decrease in the antibiotic resistance level of resistant bacteria. (nature.com)
  • Evolutionists frequently point to the development of antibiotic resistance by bacteria as a demonstration of evolutionary change. (trueorigin.org)
  • Porins are water-filled pores and channels found in the membranes of bacteria and eukaryotes. (wikipedia.org)
  • They are present in the outer membrane of gram-negative bacteria and some gram-positive mycobacteria (mycolic acid-containing actinomycetes), the outer membrane of mitochondria, and the outer chloroplast membrane. (wikipedia.org)
  • Porins are also found in eukaryotes, specifically in the outer membranes of mitochondria and chloroplasts. (wikipedia.org)
  • Gram-negative bacteria and mitochondria are both covered by two distinct biological membranes. (biochemj.org)
  • OMP porins are present in the outer membranes of Gram-negative bacteria, mitochondria and plastids. (tcdb.org)
  • Carbapenem resistance decreased markedly when the plasmid host had a wild-type complement of porins. (asm.org)
  • Here, evidence is provided that defects in porin expression dramatically increase the resistance of Mycobacterium smegmatis and Mycobacterium chelonae to glutaraldehyde and another aldehyde disinfectant, ortho -phthalaldehyde. (asm.org)
  • Since defects in porin activity also dramatically increased the resistance of M. chelonae to drugs, there is thus some concern that the widespread use of glutaraldehyde and ortho -phthalaldehyde in clinical settings may select for drug-resistant bacteria. (asm.org)
  • We show that the inability to import ammonia via the Amt gas channel or to synthesize polyamines prevent modification in the resistance profile of aerially exposed bacteria. (wiley.com)
  • Strikingly, antibiotic-resistant bacteria show a high frequency of collateral sensitivity to antimicrobial peptides, whereas cross-resistance is relatively rare. (nature.com)
  • These advances allow the identification of antimicrobial peptide-antibiotic combinations that enhance antibiotic activity against multidrug-resistant bacteria and slow down de novo evolution of resistance. (nature.com)
  • 2014). Porin involvement in cephalosporin and carbapenem resistance of Burkholderia pseudomallei . (tcdb.org)
  • Horizontal transfer, though, does not account for the origin of resistance genes, only their spread among bacteria. (trueorigin.org)
  • Acquiring resistance to a specific antibiotic provides a clear benefit to the bacterium when exposed to that antibiotic. (trueorigin.org)
  • 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)
  • The amino acid composition of the porin β strands are unique in that polar and nonpolar residues alternate along them. (wikipedia.org)
  • These specificities are determined by the threshold sizes of the porins, and the amino acid residues lining them. (wikipedia.org)
  • Using intrinsic protein fluorescence, it was shown that different conditions of pseudotuberculosis bacteria cultivation (temperature, medium, growth phase) led to the changes in spectral properties of porin fluorescence due to the redistribution of the contributions of tyrosine and different classes of tryptophan residues to the total protein emission. (chemweb.com)
  • 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)
  • Peters D, Ulusu Y, Waller H, Lakey J. Protein engineering of Caf1 from the plague bacterium Yersinia pestis for tissue engineering applications . (ncl.ac.uk)
  • Here we show that a combination of high-resolution electrophysiology, new noise-filtering analysis protocols and atomistic biomolecular simulations reveals weak binding events between the β-lactam antibiotic ampicillin and the porin PorB from the pathogenic bacterium Neisseria meningitidis . (nature.com)
  • Many bacteria become resistant by acquiring genes from plasmids or transposons via horizontal gene transfer. (trueorigin.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)
  • The permeation of most antibiotics through the outer membrane of Gram-negative bacteria occurs through porin channels. (nature.com)
  • are unique environmental, Gram-negative, obligate intracellular bacteria maintained in nature through vertical transmission in trematodes ( 16 , 17 , 39 , 42 ). (asm.org)
  • Gram-negative bacteria generally have porins spanning their outer membranes. (asm.org)
  • V ibrio cholerae is a Gram-negative bacterium that causes the potentially fatal human disease cholera. (pnas.org)
  • In gram-negative bacteria, the inner membrane is the major permeability barrier. (wikipedia.org)
  • Porins were first discovered in gram-negative bacteria, but gram-positive bacteria with both types of porins have been found. (wikipedia.org)
  • They exhibit similar transport functions but have a more limited variety of porins, compared to the distribution found in gram-negative bacteria. (wikipedia.org)
  • Gram-negative bacteria are protected by an outer membrane in which trimeric channels, the porins, facilitate the passage of small solutes. (nih.gov)
  • Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial differentiation. (wikipedia.org)
  • Gram-negative bacteria are found everywhere, in virtually all environments on Earth that support life. (wikipedia.org)
  • Several classes of antibiotics have been designed to target gram-negative bacteria, including aminopenicillins, ureidopenicillins, cephalosporins, beta-lactam-betalactamase combinations (e.g. pipercillin-tazobactam), Folate antagonists, quinolones, and carbapenems . (wikipedia.org)
  • [3] Since 1987, the monophyly of the gram-negative bacteria has been disproven with molecular studies . (wikipedia.org)
  • Gram-positive bacteria are also referred to as monoderms having one membrane, and gram-negative bacteria are also referred to as diderms , having two membranes. (wikipedia.org)
  • These groups are often thought of as lineages, with gram-negative bacteria more closely related to one another than to gram-positive bacteria. (wikipedia.org)
  • The gram-negative bacteria resides in soil, water, dairy products and inhabits a natural flora in the gastrointestinal tract of animals as well as humans. (kenyon.edu)
  • Enterobacteriaceae may account for 80% of clinically significant isolates of gram-negative bacilli and for 50% of clinically significant bacteria in clinical microbiology laboratories. (kenyon.edu)
  • Enterbacter aerogenes is a gram-negative, rod shaped bacterium that contains flagella surrounding it's outer surface. (kenyon.edu)
  • We previously demonstrated that long-term continuous exposure to increased concentration of tachyplesin I can induce resistant Gram-negative bacteria. (dovepress.com)
  • Pseudomonas aeruginosa ( P. aeruginosa ) is a Gram-negative and ubiquitous environmental bacterium. (dovepress.com)
  • Lipopolysaccharide (LPS) of Gram-negative bacteria and several surface components of Gram-positive bacteria utilize CD14 and CD11a/18 as cellular receptors to induce expression and release of cytokines. (microbiologyresearch.org)
  • Of the surface components of Gram-negative bacteria, porins exhibit a biological activity similar to that of LPS. (microbiologyresearch.org)
  • Furthermore, the predicted secondary structure of the C-terminal, surface-exposed region of OprF has high structural identity to the OmpA domain of several other Gram-negative bacteria, one of which is known to bind C3b. (asm.org)
  • Therefore, these findings provide new insights into the biology of complement interactions with P. aeruginosa and other Gram-negative bacteria. (asm.org)
  • B. Porins and ion channels have a permanent hole that passes from one side of the membrane to the other through which solutes pass whereas transporters do not. (studyblue.com)
  • Two types of porins exist to transport different materials- general and selective. (wikipedia.org)
  • Some porins are cation-selective, others are anion-selective and still others are selective for specific compounds (e.g., sugars, nucleotides, phosphate, pyrophosphate). (tcdb.org)
  • Additionally, porins can regulate permeability and prevent lysis by limiting the entry of detergents into the cell. (wikipedia.org)
  • It has been possible to isolate a number porins in their active forms and generate monomer crystal structures. (kenyon.edu)
  • 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)
  • Additionally, the outer leaflet of this membrane comprises a complex lipopolysaccharide (LPS) whose lipid A component can cause a toxic reaction when these bacteria are lysed by immune cells. (wikipedia.org)
  • Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. (nih.gov)
  • Considering all these data, it is possible to correlate the spatial structure and functional activity of porin samples isolated under different cultivation conditions of bacteria and the composition of the outer membrane lipid matrix. (chemweb.com)
  • We therefore provide here the first detailed molecular characterization of widespread, long-range chemical interference between physically separated bacteria. (wiley.com)
  • 2011). Characterization of a porin channel in the endosymbiont of the trypanosomatid protozoan Crithidia deanei. (tcdb.org)
  • Gram-positive bacteria lack outer membranes, so these porin channels are instead bound to specific lipids within the cell walls. (wikipedia.org)
  • Bacterium cannot make cell walls - necessary for shape - Specifically inhibits transpeptidase resulting in a weak cell wall. (flashcardmachine.com)
  • What enzyme crosslinks cell walls in bacteria? (flashcardmachine.com)
  • The decreased influx rates of antibiotics into the bacteria caused by altered antibiotic-channel interactions can be aggravated by the overexpression of efflux pumps, which in combination, often leads to highly resistant phenotypes 22 . (nature.com)
  • However, interactions between drugs and porins are often weak and short-lived, and therefore difficult to characterise. (nature.com)
  • Whereas volatile compounds constitute a large class of potential infochemicals, their role in bacteria-bacteria interactions remains vastly unexplored. (wiley.com)
  • However, volatile compounds have been studied primarily in a context of inter-kingdom responses and little is known about their potential roles in bacteria-to-bacteria interactions. (wiley.com)
  • Sequence comparisons and three-dimensional structural analyses suggest that many of the families described under category 1.B are related (see porin superfamilies in TCDB and ( Reddy and Saier 2016 ). (tcdb.org)
  • This bacterium is often the causative agent of acute and chronic infections of the airway, sepsis, burn wounds, and skin infections. (asm.org)
  • Collateral sensitivity in multidrug-resistant bacteria arises partly through regulatory changes shaping the lipopolysaccharide composition of the bacterial outer membrane. (nature.com)
  • Fig. 3: Altered membrane composition in antibiotic-resistant bacteria contributes to increased sensitivity to antimicrobial peptides. (nature.com)
  • Fig. 4: A putative mechanism underlying collateral sensitivity of antibiotic-resistant bacteria to cationic antimicrobial peptides. (nature.com)
  • Emergence of NDM-1 has been considered as a global threat because bacteria which possess this metallo- β -lactamase are resistant to almost all β -lactam antibiotics, aminoglycosides, fluoroquinolones, and other classes of antibiotics. (hindawi.com)
  • Porins are composed of beta sheets (β sheets) made up of beta strands (β strands) which are linked together by beta turns on the cytoplasmic side and long loops of amino acids on the other. (wikipedia.org)
  • The β barrels that make up a porin are composed of as few as eight β strands to as many as twenty-two β strands. (wikipedia.org)
  • Depending on the size of the porin, the interior of the protein may either be filled with water, have up to two β strands folded back into the interior, or contain a "stopper" segment composed of β strands. (wikipedia.org)
  • Strand number (n) is the amount of β strands in the porin, and barrel radius (R) refers to the radius of the opening of the porin. (wikipedia.org)
  • The current study uncovers a role for ToxR-dependent porin modulation in V. cholerae virulence. (pnas.org)
  • The outer membrane is more permeable to hydrophilic substances, due to the presence of porins. (wikipedia.org)
  • A few porins display substrate-specificity in addition to general diffusion properties. (kenyon.edu)
  • Maltoporin, also known as the LamB porin, is among the best studied examples of the substrate-specific porins. (kenyon.edu)
  • A. .Transporters exhibit a conformational change when substrate binds but porins and ion channels do not. (studyblue.com)
  • These sequences are putative porins. (ebi.ac.uk)
  • Neorickettsia sennetsu is an obligate intracellular bacterium of monocytes and macrophages and is the etiologic agent of human Sennetsu neorickettsiosis. (asm.org)
  • Coexistence of CD14-dependent and independent pathway for stimulation of human monocytes by gram-positive bacteria. (microbiologyresearch.org)
  • A nonlinear dependence of channel conductivity on salt concentration in the aqueous phase was found for the P-2 protein, which is typical of marine bacterial porins. (deepdyve.com)
  • We found that the isolated outer membrane of N. sennetsu had porin activity, as measured by a proteoliposome swelling assay. (asm.org)
  • And Okabe published that 72.1 percent of the patients with root canals had bacteremia (i.e. bacteria in the blood that were identical to those found in the root canal tooth). (mercola.com)
  • These findings illustrate that the degree of openness of porins can be regulated by compounds naturally found in bacteria. (nih.gov)
  • It was found that the protein isolated from the colonial culture of pseudotuberculosis bacteria grown at low temperature has the most compact structure. (chemweb.com)
  • Spatial features of the porin samples were found to affect their functional activities. (chemweb.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)
  • While the structure of many porins have been determined using X-ray crystallography, the alternative method of sequencing protein primary structure may also be used instead. (wikipedia.org)
  • Maltoporin is also one of the many porins which contains a bacteriophage recognition sequence. (kenyon.edu)
  • Although there is little to no sequence homology among porins, they often share a strong structural resemblance. (kenyon.edu)
  • Our results provide a rationale for the determinants that govern the binding and permeation of zwitterionic antibiotics in porin channels. (nature.com)
  • Most porins form general, non-specific channels that are regulated by environmental changes. (kenyon.edu)
  • Some electrophysiological studies find reconstituted porins in a mostly open state, while those done with the patch-clamp technique performed on live cells suggest that the vast majority of the native channels are closed. (nih.gov)
  • We present here current measurements through porins from reconstituted outer membrane, which demonstrate that bacterial metabolites, the MDO's, which bathe the periplasmic side of the outer membrane, induce the channels to close. (nih.gov)
  • All porins form homotrimers in the outer membrane, meaning that three identical porin subunits associate together to form a porin super-structure with three channels. (wikipedia.org)
  • Porin-like channels have also been discovered in archaea. (wikipedia.org)
  • The cell wall porins of these members of the order Actinomycetales share common features because they form large and water-filled channels that contain negative point charges. (nih.gov)
  • C. Porins and ion channels mediate passive transport, while transporters are associated with both passive and active transport. (studyblue.com)
  • Our data provide evidence that OprF (an outer membrane porin, highly conserved in the Pseudomonadaceae ) binds C3b. (asm.org)
  • Solovyeva, T. 2013-03-25 00:00:00 Outer membrane (OM) fractions were isolated from marine bacteria of the genus Pseudoalteromonas (P. haloplanktis, P. tetraodonis, and Pseudoalteromonas sp. (deepdyve.com)
  • Dr. Price and Mayo identified dozens of diseases related to bacterial toxins created by bacteria in root canals. (mercola.com)
  • Toxins from these bacteria together with mercury from dental amalgam have the ability to alter your DNA. (mercola.com)
  • This article discusses how toxins from these bacteria together with mercury from dental amalgam increase the potential for disease. (bewellbuzz.com)
  • The role of sphingolipids as receptors of bacteria, viruses, and toxins and also as ligands of proteinaceous receptors involved in the cell-cell signaling in animals is considered. (chemweb.com)