Search results for "Porins"

Sus1, a functional component of the SAGA histone acetylase complex and the nuclear pore-associated mRNA export machinery

2004

12 páginas, 7 figuras, 1 tabla. Material suplementario en: https://doi.org/10.1016/S0092-8674(03)01025-0. The SUS1 sequences have been deposited in GenBank with the accession number AY278445.

Insertion of a malE B-Galactosidase fusion protein into the envelope of Escherichia coli disrupts biogenesis of outer membrane proteins and processin…

1982

The synthesis of a membrane-bound MalE ,B-galactosidase hybrid protein, when induced by growth of Escherichia coli on maltose, leads to inhibition of cell division and eventually a reduced rate of mass increase. In addition, the relative rate of synthesis of outer membrane proteins, but not that of inner membrane proteins, was reduced by about 50%o. Kinetic experiments demonstrated that this reduction coincided with the period of maximum synthesis of the hybrid protein (and another maltose-inducible protein, LamB). The accumulation of this abnormal protein in the envelope therefore appeared specifically to inhibit the synthesis, the assembly of outer membrane proteins, or both, indicating t…

Extended-Spectrum ß-Lactamase, AmpC-Producing, and Fluoroquinolone-Resistant Escherichia coli in Retail Broiler Chicken Meat, Italy.

2015

Background: Globally, antimicrobial drug-resistant Escherichia coli is among the most common etiological agents of invasive disease in humans. In Europe, increasing proportions of infections due to third-generation cephalosporins and/or fluoroquinolone-resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. E. coli from poultry are those more closely linked to human E. coli, but lack of reliable data makes it difficult to assess the attributable risk of different food sources. In the present study, our objective was to investigate the antimicrobial resistance profile, phylogenetic background, and virulence factors of E. coli isolates from broiler chicken meat sold at reta…

Possible coumarin-like mechanism of action for cephalosporins.

1984

In three patients treated with cephalosporins (one patient with latamoxef, two patients with cefazedone) vitamin K1 was injected to investigate whether this was followed by an increase in vitamin K1 2,3-epoxide plasma concentrations as compared to controls. Such a rise in K1-epoxide concentrations in the plasma can be demonstrated following treatment with coumarins. This reflects an inhibition of the vitamin K1-epoxide reductase in the liver. Coumarins are thought to induce hypoprothrombinaemia by such a mechanism. In all three patients we found a considerable increase in the vitamin K1-epoxide plasma concentrations following injection of 10 mg vitamin K1, whereas in normal subjects only tr…

Studies on the interaction of C1q,a subcomponent of the first component of complement, with porins fromSalmonella minnesotaincorporated into artifici…

1990

AbstractPurified outer membrane proteins (OMP) of Salmonella minnesota, Re-form, were incorporated into liposomes. These induced in macrophages a chemiluminescence signal identical to that of the intact Re-form. This signal was abolished by preincubation of porin-containing liposomes with purified C1q. Incorporation of isolated OMP into black lipid membranes (BLM) resulted in channel-formation which could not be inhibited by isolated C1q. Additionally, incubation of OMP-containing liposomes with BLM resulted in pore-formation within the BLM. This was amplified when lipid A was present within the liposomes. Preincubation of OMP-containing liposomes with purified C1q abolished pore-formation …

Penetration of 2% cyclosporin eyedrops into human aqueous humour.

1989

The penetration into the eye and the systemic absorption of 2% cyclosporin eye drops were determined by polarisation immunofluorescent assay of cyclosporin in the aqueous humour and plasma of 30 patients at the time of cataract surgery. The results were then compared with the corresponding results after oral administration at a dosage of 5 mg/kg/day to three further patients. The maximum intraocular concentration (24 (SD 9) mg/l) was achieved four hours after topical administration. This level was slightly less than that found in aqueous humour (28 (SD 10) mg/l) 12 hours after systemic administration of the drug at a dosage of 5 mg/kg/day. Both these levels are below the minimum therapeutic…

Viroporins, Examples of the Two-Stage Membrane Protein Folding Model

2015

Viroporins are small, α-helical, hydrophobic virus encoded proteins, engineered to form homo-oligomeric hydrophilic pores in the host membrane. Viroporins participate in multiple steps of the viral life cycle, from entry to budding. As any other membrane protein, viroporins have to find the way to bury their hydrophobic regions into the lipid bilayer. Once within the membrane, the hydrophobic helices of viroporins interact with each other to form higher ordered structures required to correctly perform their porating activities. This two-step process resembles the two-stage model proposed for membrane protein folding by Engelman and Poppot. In this review we use the membrane protein folding …

Optimizing ceftolozane-tazobactam dosage during continuous renal replacement therapy: additional insights

2019

Mechanisms of irreversible aquaporin-10 inhibition by organogold compounds studied by combined biophysical methods and atomistic simulations

2021

Abstract The inhibition of glycerol permeation via human aquaporin-10 (hAQP10) by organometallic gold complexes has been studied by stopped-flow fluorescence spectroscopy, and its mechanism has been described using molecular modelling and atomistic simulations. The most effective hAQP10 inhibitors are cyclometalated Au(III) C^N compounds known to efficiently react with cysteine residues leading to the formation of irreversible C–S bonds. Functional assays also demonstrate the irreversibility of the binding to hAQP10 by the organometallic complexes. The obtained computational results by metadynamics show that the local arylation of Cys209 in hAQP10 by one of the gold inhibitors is mapped int…