Porin
Mostrando 13-24 de 529 artigos, teses e dissertações.
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13. Identification and Characterization of a New Porin Gene of Klebsiella pneumoniae: Its Role in β-Lactam Antibiotic Resistance
Klebsiella pneumoniae porin genes were analyzed to detect mutations accounting for the porin deficiency observed in many β-lactam-resistant strains. PCR and Southern blot analysis revealed the existence of a third porin gene in addition to the OmpK36 and OmpK35 porin genes previously described. This new porin gene was designated ompK37 and is present in all
American Society for Microbiology.
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14. Evidence for the Presence of a Porin in the Membrane of Glyoxysomes of Castor Bean.
Glyoxysomes of endosperm tissue of castor bean (Ricinus communis L.) seedlings were solubilized in a detergent and added to a lipid bilayer. Conductivity measurements revealed that the glyoxysomal preparation contained a porin-like channel. Using an electrophysiological method, which we established for semiquantitative determination of porin activity, we wer
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15. Influence of Culture Conditions on Expression of the 40-Kilodalton Porin Protein of Vibrio anguillarum Serotype O2
Vibrio anguillarum serotype O2 strains express a 40-kDa outer membrane porin protein. Immunoblot analysis revealed that antigenic determinants of the V. anguillarum O2 40-kDa porin were conserved within bacterial species of the genus Vibrio. The relative amounts of the V. anguillarum O2 40-kDa porin were enhanced by growth of V. anguillarum O2 in CM9 medium
American Society for Microbiology.
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16. Diffusion of aminoglycoside antibiotics across the outer membrane of Escherichia coli.
The diffusion of aminoglycoside antibiotics (gentamicin, kanamycin, streptomycin, fradiomycin, lividomycin, and mannosylparomomycin) through porin pores was examined in vitro by the liposome swelling technique, using vesicle membranes reconstituted from phospholipids and purified porin trimers. Results showed that aminoglycoside antibiotics diffuse through p
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17. Targeting of the pro-apoptotic VDAC-like porin (PorB) of Neisseria gonorrhoeae to mitochondria of infected cells
Infection of cell cultures with Neisseria gonorrhoeae results in apoptosis that is mediated by the PorB porin. During the infection process porin translocates from the outer bacterial membrane into host cell membranes where its channel activity is regulated by nucleotide binding and voltage-dependent gating, features that are shared by the mitochondrial volt
Oxford University Press.
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18. Expression of large amounts of neisserial porin proteins in Escherichia coli and refolding of the proteins into native trimers.
Porins from different neisserial strains and species have been shown to have differences in both primary amino acid sequence and biophysical characteristics as observed by functional assays. A closer examination of how the changes in the primary amino acid sequence of Neisseria porin molecules correlate with these observed biophysical changes has been impede
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19. Neisseria gonorrhoeae Porin Modifies the Oxidative Burst of Human Professional Phagocytes
A hallmark of infection with the gram-negative bacterium Neisseria gonorrhoeae is the local infiltration and subsequent activation of polymorphonuclear neutrophils. Several gonococcal outer membrane proteins are involved in the interaction with and the activation of these phagocytes, including gonococcal porin, the most abundant protein in the outer membrane
American Society for Microbiology.
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20. Purification and Characterization of Porin from Corn (Zea mays L.) Mitochondria.
Mitochondrial porin from corn (Zea mays L. B 73) shoots was solubilized with lauryl(dimethyl)-amine oxide and purified by chromatography on a hydroxyapatite:celite column. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified protein had an apparent molecular mass of 35 kD. When reconstituted in planar lipid bilayer membranes the porin f
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21. Outer Membrane Profiles of Clonally Related Klebsiella pneumoniae Isolates from Clinical Samples and Activities of Cephalosporins and Carbapenems
Fifteen isolates of Klebsiella pneumoniae producing extended-spectrum β-lactamases (ESBLs) isolated during a nosocomial outbreak were studied. The strains belonged to the same clonal type, as shown by pulsed-field gel electrophoretic analysis of chromosomal DNA. All the isolates were resistant to extended-spectrum cephalosporins, aztreonam, gentamicin, and
American Society for Microbiology.
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22. Escherichia coli outer membrane protein K is a porin.
Protein K is an outer membrane protein found in pathogenic encapsulated strains of Escherichia coli. We present evidence here that protein K is structurally and functionally related to the E. coli K-12 porin proteins (OmpF, OmpC, and PhoE). Protein K was found to cross-react with antibody to OmpF protein and to share 8 out of 17 peptides in common with the O
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23. Subunit constituent of the porin trimers that form the permeability channels in the outer membrane of Salmonella typhimurium.
The polypeptide composition of the functional porin trimers that produced the permeability channels in the outer membrane of Salmonella typhimurium was examined on two-dimensional slab gels. The results suggested that the majority of porin trimers from strains producing mixed species of porin polypeptides consisted of homologous subunit polypeptides. The pre
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24. Immunobiological activities of a porin fraction isolated from Fusobacterium nucleatum ATCC 10953.
From Fusobacterium nucleatum ATCC 10953 cell envelope fraction whose inner membranes had been removed by treatment with sodium N-lauroyl sarcosinate, an outer membrane protein (37,000 Mr in a native state) was prepared by extraction with lithium dodecyl sulfate. The protein thus obtained showed distinct porin activity, namely, the ability to form hydrophilic