Porins and specific diffusion channels in bacterial outer membranes.
نویسندگان
چکیده
منابع مشابه
In Silico Structure and Sequence Analysis of Bacterial Porins and Specific Diffusion Channels for Hydrophilic Molecules: Conservation, Multimericity and Multifunctionality
Diffusion channels are involved in the selective uptake of nutrients and form the largest outer membrane protein (OMP) family in Gram-negative bacteria. Differences in pore size and amino acid composition contribute to the specificity. Structure-based multiple sequence alignments shed light on the structure-function relations for all eight subclasses. Entropy-variability analysis results are co...
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Determination of the rates of diffusion of beta-lactam antibiotics through purified Pseudomonas aeruginosa porins C, D2, and E in liposomes yielded the following results. (i) The rates of carbapenem (imipenem and meropenem) diffusion through the protein D2 pore were roughly 2 to 70 times higher than those through other porin pores. It is not clear why the protein D2 pore allowed rapid diffusion...
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It is now well recognized that the outer membranes of gram-negative bacteria serve as molecular sieves which permit the passage of small hydrophilic molecules of sizes below a given cutoff, i.e., the exclusion limit (21, 27). This sieving property, which permits uptake of small substrate molecules but excludes potentially harmful enzymes and other large hydrophilic molecules, is due to a class ...
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The purified outer membrane proteins of Pseudomonas aeruginosa were reconstituted with phosphatidylcholine and dicetylphosphate into membrane vesicles, and these were tested by the liposome swelling method for the diffusion of saccharides with different Mr. Proteins C (Mr, 70,000), D (Mr, 46,000), and E (Mr, 43,000) were found to confer the monosaccharide-permeable pores in the reconstituted li...
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Phosphate starvation induced oligomeric proteins from the outer membranes of Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas aureofaciens, and Pseudomonas chlororaphis were purified to homogeneity. The incorporation of the purified proteins into planar lipid bilayer membranes resulted in stepwise increases in membrane conductance. Single channel conductance experiments demonstrated tha...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1994
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)41716-9